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Sample records for improved perfectly matched

  1. Efficiency improved scalar wave low-rank extrapolation with an effective perfectly matched layer

    NASA Astrophysics Data System (ADS)

    Chen, Hanming; Zhou, Hui; Xia, Muming

    2017-02-01

    Low-rank extrapolation is a relatively new method for seismic wave simulation. However, the low-rank method involved requires several fast Fourier transforms (FFTs) per time step, and the number of FFTs increases with the time-stepping size and complexity of the model, which leads to high computational cost at each step. To reduce the cost per time step, a more efficient low-rank extrapolation scheme is presented by splitting the original wave propagator into two parts. The first part represents the traditional pseudo-spectral operator, and is calculated by FFT directly. The residual part compensates the time-stepping error, and is approximated by low-rank decomposition. Compared with the conventional low-rank extrapolation scheme, the improved extrapolation scheme enables using a lower rank for the decomposition to attain similar approximation accuracy, which reduces the number of floating-point operations per time step, and thus reduces the total computational cost. To avoid the wraparound effect caused by FFTs, we develop an effective split perfectly matched layer (PML) to absorb outgoing waves near the boundary. Numerical examples verify the accuracy of the developed low-rank extrapolation scheme and the effectiveness of the PML.

  2. Perfect and improving

    NASA Astrophysics Data System (ADS)

    Kerr, Robert

    2008-09-01

    As a child I always used to wonder how someone could be described as a "perfect stranger". Not only did I not know any strangers (by definition), I also didn't really see how anyone could be called perfect - that seemed a bridge too far. Nowadays, however, in my early dotage/mid-life crisis/eternally youthful existence (depending on whether you are talking to my friends, family or me) I begin to see that perhaps at last I have achieved a level of perfection not anticipated in my youth. You see, I have almost completely transmogrified myself from a real physics teacher into a pretend sociologist. I am now, and intend to continue to be for some time, a perfect fraud.

  3. An ACCESS Printout on School Based Improvement and Effective Schools: A Perfect Match for Bottom-Up Reform.

    ERIC Educational Resources Information Center

    National Committee for Citizens in Education, Columbia, MD.

    School-based management and improvement, supported by parent and community involvement, offer the most promising route to lasting reform in the public schools. Following an extensive introduction (part I) outlining school-based management and improvement concepts, the effective schools connection, the Dade County (Florida) experience, and 10…

  4. An unsplit Convolutional perfectly matched layer technique improved at grazing incidence for the differential anisotropic elastic wave equation: application to 3D heterogeneous near surface slices.

    NASA Astrophysics Data System (ADS)

    Martin, R.; Komatitsch, D.

    2007-05-01

    In geophysical exploration, high computational cost of full waveform inverse problem can be drastically reduced by implementing efficient boundary conditions. In many regions of interest for the oil industry or geophysical exploration, nearly tabular geological structures can be handled and analyzed by setting receivers in wells or/and at large offset. Then, the numerical modelling of waves travelling in thin slices along wells and near surface structures can provide very fast responses if highly accurate absorbing conditions around the slice are introduced in the wave propagation modelling. Here we propose then a Convolutional version of the well known Perfectly Matched layer technique. This optimized version allows the generation of seismic waves travelling close to the boundary layer at almost grazing incidence, which allows the treatment of thin 3D slices. The Perfectly Matched Layer (PML) technique, introduced in 1994 by Bérenger for Maxwell's equations, has become classical in the context of numerical simulations in electromagnetics, in particular for 3D finite difference in the time domain (FDTD) calculations. One of the most attractive properties of a PML model is that no reflection occurs at the interface between the physical domain and the absorbing layer before truncation to a finite-size layer and discretization by a numerical scheme. Therefore, the absorbing layer does not send spurious energy back into the medium. This property holds for any frequency and angle of incidence. However, the layer must be truncated in order to be able to perform numerical simulations, and such truncation creates a reflected wave whose amplitude is amplified by the discretization process. In 2001, Collino and Tsogka introduced a PML model for the elastodynamics equation written as a first-order system in velocity and stress with split unknowns, and discretized it based on the standard 2D staggered-grid finite-difference scheme of Virieux (1986). Then in 2001 and 2004

  5. Asymmetric perfectly matched layer for the absorption of waves

    SciTech Connect

    Vay, Jean-Luc

    2002-02-10

    The Perfectly Matched Layer (PML) has become a standard for comparison in the techniques that have been developed to close the system of Maxwell equations (more generally wave equations) when simulating an open system. The original Berenger PML formulation relies on a split version of Maxwell equations with numerical electric and magnetic conductivities. They present here an extension of this formulation which introduces counterparts of the electric and magnetic conductivities affecting the term which is spatially differentiated in the equations. they phase velocity along each direction is also multiplied by an additional coefficient. They show that, under certain constraints on the additional numerical coefficients, this ''medium'' does not generate any reflection at any angle and any frequency and is then a Perfectly Matched Layer. Technically it is a super-set of Berenger's PML to which it reduces for a specific set of parameters and like it, it is anisotropic. However, unlike the PML, it introduces some asymmetry in the absorption rate and is therefore labeled an APML for Asymmetric Perfectly Matched Layer. They present here the numerical considerations that have led them to introduce such a medium as well as its theory. Several finite-different numerical implementations are derived (in one, two and three dimensions) and the performance of the APML is contrasted with that of the PML in one and two dimensions. Using plane wave analysis, they show that the APML implementations lead to higher absorption rates than the considered PML implementations. Although they have considered in this paper the finite-different discretization of Maxwell-like equations only, the APML system of equations may be used with other discretization schemes, such as finite-elements, and may be applied to other equations, for applications beyond electromagnetics.

  6. Improved and perfect actions in discrete gravity

    SciTech Connect

    Bahr, Benjamin; Dittrich, Bianca

    2009-12-15

    We consider the notion of improved and perfect actions within Regge calculus. These actions are constructed in such a way that they - although being defined on a triangulation - reproduce the continuum dynamics exactly, and therefore capture the gauge symmetries of general relativity. We construct the perfect action in three dimensions with a cosmological constant, and in four dimensions for one simplex. We conclude with a discussion about Regge calculus with curved simplices, which arises naturally in this context.

  7. AN FDTD ALGORITHM WITH PERFECTLY MATCHED LAYERS FOR CONDUCTIVE MEDIA. (R825225)

    EPA Science Inventory

    We extend Berenger's perfectly matched layers (PML) to conductive media. A finite-difference-time-domain (FDTD) algorithm with PML as an absorbing boundary condition is developed for solutions of Maxwell's equations in inhomogeneous, conductive media. For a perfectly matched laye...

  8. Development of a Perfectly Matched Layer Technique for a Discontinuous-Galerkin Spectral-Element Method

    NASA Technical Reports Server (NTRS)

    Garai, Anirban; Diosady, Laslo T.; Murman, Scott M.; Madavan, Nateri K.

    2016-01-01

    The perfectly matched layer (PML) technique is developed in the context of a high- order spectral-element Discontinuous-Galerkin (DG) method. The technique is applied to a range of test cases and is shown to be superior compared to other approaches, such as those based on using characteristic boundary conditions and sponge layers, for treating the inflow and outflow boundaries of computational domains. In general, the PML technique improves the quality of the numerical results for simulations of practical flow configurations, but it also exhibits some instabilities for large perturbations. A preliminary analysis that attempts to understand the source of these instabilities is discussed.

  9. The perfect match: Do criminal stereotypes bias forensic evidence analysis?

    PubMed

    Smalarz, Laura; Madon, Stephanie; Yang, Yueran; Guyll, Max; Buck, Sarah

    2016-08-01

    This research provided the first empirical test of the hypothesis that stereotypes bias evaluations of forensic evidence. A pilot study (N = 107) assessed the content and consensus of 20 criminal stereotypes by identifying perpetrator characteristics (e.g., sex, race, age, religion) that are stereotypically associated with specific crimes. In the main experiment (N = 225), participants read a mock police incident report involving either a stereotyped crime (child molestation) or a nonstereotyped crime (identity theft) and judged whether a suspect's fingerprint matched a fingerprint recovered at the crime scene. Accompanying the suspect's fingerprint was personal information about the suspect of the type that is routinely available to fingerprint analysts (e.g., race, sex) and which could activate a stereotype. Participants most often perceived the fingerprints to match when the suspect fit the criminal stereotype, even though the prints did not actually match. Moreover, participants appeared to be unaware of the extent to which a criminal stereotype had biased their evaluations. These findings demonstrate that criminal stereotypes are a potential source of bias in forensic evidence analysis and suggest that suspects who fit criminal stereotypes may be disadvantaged over the course of the criminal justice process. (PsycINFO Database Record

  10. Error Control with Perfectly Matched Layer or Damping Layer Treatments for Computational Aeroacoustics with Jet Flows

    NASA Technical Reports Server (NTRS)

    Goodrich, John W.

    2009-01-01

    In this paper we show by means of numerical experiments that the error introduced in a numerical domain because of a Perfectly Matched Layer or Damping Layer boundary treatment can be controlled. These experimental demonstrations are for acoustic propagation with the Linearized Euler Equations with both uniform and steady jet flows. The propagating signal is driven by a time harmonic pressure source. Combinations of Perfectly Matched and Damping Layers are used with different damping profiles. These layer and profile combinations allow the relative error introduced by a layer to be kept as small as desired, in principle. Tradeoffs between error and cost are explored.

  11. Striving for perfection and falling short: The influence of goals on probability matching.

    PubMed

    Gao, Jie; Corter, James E

    2015-07-01

    Probability matching in sequential prediction tasks is argued to occur because participants implicitly adopt the unrealistic goal of perfect prediction of sequences. Biases in the understanding of randomness then lead them to generate mixed rather than pure sequences of predictions in attempting to achieve this goal. In Study 1, N = 350 participants predicted 100 trials of a binary-outcome event. Two factors were manipulated: probability bias (the outcomes were equiprobable or distributed with a 75%-25% bias), and goal type-namely, whether single-trial predictions or the perfect prediction of four-trial sequences was emphasized and rewarded. As we hypothesized, predicting sequences led to more probability-matching behavior than did predicting single trials, for both the bias and no-bias conditions. In Study 1B, we added a control condition to distinguish the effects of the grouped presentation of trials from the effects of sequence-level perfect-prediction rewards. The results supported goal type rather than presentation format as the cause of the Study 1 differences in matching between the sequence and single-trial conditions. In Study 2, all participants (N = 300) predicted the outcomes for five-trial sequences, but with different goal levels being rewarded: 60%, 80%, or 100% correct predictions. The 100% goal resulted in the most probability matching, as hypothesized. Paradoxically, using the inferior strategy of probability matching may be triggered by adopting an unrealistic perfect-prediction goal.

  12. Perfectly matched layer for an elastic parabolic equation model in ocean acoustics

    NASA Astrophysics Data System (ADS)

    Xu, Chuanxiu; Zhang, Haigang; Piao, Shengchun; Yang, Shi'e.; Sun, Sipeng; Tang, Jun

    2017-02-01

    The perfectly matched layer (PML) is an effective technique for truncating unbounded domains with minimal spurious reflections. A fluid parabolic equation (PE) model applying PML technique was previously used to analyze the sound propagation problem in a range-dependent waveguide (Lu and Zhu, 2007). However, Lu and Zhu only considered a standard fluid PE to demonstrate the capability of the PML and did not take improved one-way models into consideration. They applied a [1/1] Padé approximant to the parabolic equation. The higher-order PEs are more accurate than standard ones when a very large angle propagation is considered. As for range-dependent problems, the techniques to handle the vertical interface between adjacent regions are mainly energy conserving and single-scattering. In this paper, the PML technique is generalized to the higher order elastic PE, as is to the higher order fluid PE. The correction of energy conserving is used in range-dependent waveguides. Simulation is made in both acoustic cases and seismo-acoustic cases. Range-independent and range-dependent waveguides are both adopted to test the accuracy and efficiency of this method. The numerical results illustrate that a PML is much more effective than an artificial absorbing layer (ABL) both in acoustic and seismo-acoustic sound propagation modeling.

  13. The Analysis and Construction of Perfectly Matched Layers for the Linearized Euler Equations

    NASA Technical Reports Server (NTRS)

    Hesthaven, J. S.

    1997-01-01

    We present a detailed analysis of a recently proposed perfectly matched layer (PML) method for the absorption of acoustic waves. The split set of equations is shown to be only weakly well-posed, and ill-posed under small low order perturbations. This analysis provides the explanation for the stability problems associated with the split field formulation and illustrates why applying a filter has a stabilizing effect. Utilizing recent results obtained within the context of electromagnetics, we develop strongly well-posed absorbing layers for the linearized Euler equations. The schemes are shown to be perfectly absorbing independent of frequency and angle of incidence of the wave in the case of a non-convecting mean flow. In the general case of a convecting mean flow, a number of techniques is combined to obtain a absorbing layers exhibiting PML-like behavior. The efficacy of the proposed absorbing layers is illustrated though computation of benchmark problems in aero-acoustics.

  14. Efficiency of perfectly matched layers for seismic wave modeling in second-order viscoelastic equations

    NASA Astrophysics Data System (ADS)

    Ping, Ping; Zhang, Yu; Xu, Yixian; Chu, Risheng

    2016-12-01

    In order to improve the perfectly matched layer (PML) efficiency in viscoelastic media, we first propose a split multi-axial PML (M-PML) and an unsplit convolutional PML (C-PML) in the second-order viscoelastic wave equations with the displacement as the only unknown. The advantage of these formulations is that it is easy and efficient to revise the existing codes of the second-order spectral element method (SEM) or finite-element method (FEM) with absorbing boundaries in a uniform equation, as well as more economical than the auxiliary differential equations PML. Three models which are easily suffered from late time instabilities are considered to validate our approaches. Through comparison the M-PML with C-PML efficiency of absorption and stability for long time simulation, it can be concluded that: (1) for an isotropic viscoelastic medium with high Poisson's ratio, the C-PML will be a sufficient choice for long time simulation because of its weak reflections and superior stability; (2) unlike the M-PML with high-order damping profile, the M-PML with second-order damping profile loses its stability in long time simulation for an isotropic viscoelastic medium; (3) in an anisotropic viscoelastic medium, the C-PML suffers from instabilities, while the M-PML with second-order damping profile can be a better choice for its superior stability and more acceptable weak reflections than the M-PML with high-order damping profile. The comparative analysis of the developed methods offers meaningful significance for long time seismic wave modeling in second-order viscoelastic wave equations.

  15. On absorbing boundary conditions for linearized Euler equations by a perfectly matched layer

    NASA Technical Reports Server (NTRS)

    Hu, Fang Q.

    1995-01-01

    Recently, Berenger introduced a Perfectly Matched Layer (PML) technique for absorbing electromagnetic waves. In the present paper, a perfectly matched layer is proposed for absorbing out-going two-dimensional waves in a uniform mean flow, generated by linearized Euler equations. It is well known that the linearized Euler equations support acoustic waves, which travel with the speed of sound relative to the mean flow, and vorticity and entropy waves, which travel with the mean flow. The PML equations to be used at a region adjacent to the artificial boundary for absorbing these linear waves are defined. Plane waves solutions to the PML equations are developed and wave propagation and absorption properties are given. It is shown that the theoretical reflection coefficients at an interface between the Euler and PML domains are zero, independent of the angle of incidence and frequency of the waves. As such, the present study points out a possible alternative approach for absorbing out-going waves of the Euler equations with little or no reflection in computation. Numerical examples that demonstrate the validity of the proposed PML equations are also presented.

  16. Perfectly matched layer absorbing boundary condition for nonlinear two-fluid plasma equations

    NASA Astrophysics Data System (ADS)

    Sun, X. F.; Jiang, Z. H.; Hu, X. W.; Zhuang, G.; Jiang, J. F.; Guo, W. X.

    2015-04-01

    Numerical instability occurs when coupled Maxwell equations and nonlinear two-fluid plasma equations are solved using finite difference method through parallel algorithm. Thus, a perfectly matched layer (PML) boundary condition is set to avoid the instability caused by velocity and density gradients between vacuum and plasma. A splitting method is used to first decompose governing equations to time-dependent nonlinear and linear equations. Then, a proper complex variable is used for the spatial derivative terms of the time-dependent nonlinear equation. Finally, with several auxiliary function equations, the governing equations of the absorbing boundary condition are derived by rewriting the frequency domain PML in the original physical space and time coordinates. Numerical examples in one- and two-dimensional domains show that the PML boundary condition is valid and effective. PML stability depends on the absorbing coefficient and thickness of absorbing layers.

  17. Unsplit complex frequency shifted perfectly matched layer for second-order wave equation using auxiliary differential equations.

    PubMed

    Gao, Yingjie; Zhang, Jinhai; Yao, Zhenxing

    2015-12-01

    The complex frequency shifted perfectly matched layer (CFS-PML) can improve the absorbing performance of PML for nearly grazing incident waves. However, traditional PML and CFS-PML are based on first-order wave equations; thus, they are not suitable for second-order wave equation. In this paper, an implementation of CFS-PML for second-order wave equation is presented using auxiliary differential equations. This method is free of both convolution calculations and third-order temporal derivatives. As an unsplit CFS-PML, it can reduce the nearly grazing incidence. Numerical experiments show that it has better absorption than typical PML implementations based on second-order wave equation.

  18. Perfectly Matched Layer for Linearized Euler Equations in Open and Ducted Domains

    NASA Technical Reports Server (NTRS)

    Tam, Christopher K. W.; Auriault, Laurent; Cambuli, Francesco

    1998-01-01

    Recently, perfectly matched layer (PML) as an absorbing boundary condition has widespread applications. The idea was first introduced by Berenger for electromagnetic waves computations. In this paper, it is shown that the PML equations for the linearized Euler equations support unstable solutions when the mean flow has a component normal to the layer. To suppress such unstable solutions so as to render the PML concept useful for this class of problems, it is proposed that artificial selective damping terms be added to the discretized PML equations. It is demonstrated that with a proper choice of artificial mesh Reynolds number, the PML equations can be made stable. Numerical examples are provided to illustrate that the stabilized PML performs well as an absorbing boundary condition. In a ducted environment, the wave mode are dispersive. It will be shown that the group velocity and phase velocity of these modes can have opposite signs. This results in a confined environment, PML may not be suitable as an absorbing boundary condition.

  19. A novel unsplit perfectly matched layer for the second-order acoustic wave equation.

    PubMed

    Ma, Youneng; Yu, Jinhua; Wang, Yuanyuan

    2014-08-01

    When solving acoustic field equations by using numerical approximation technique, absorbing boundary conditions (ABCs) are widely used to truncate the simulation to a finite space. The perfectly matched layer (PML) technique has exhibited excellent absorbing efficiency as an ABC for the acoustic wave equation formulated as a first-order system. However, as the PML was originally designed for the first-order equation system, it cannot be applied to the second-order equation system directly. In this article, we aim to extend the unsplit PML to the second-order equation system. We developed an efficient unsplit implementation of PML for the second-order acoustic wave equation based on an auxiliary-differential-equation (ADE) scheme. The proposed method can benefit to the use of PML in simulations based on second-order equations. Compared with the existing PMLs, it has simpler implementation and requires less extra storage. Numerical results from finite-difference time-domain models are provided to illustrate the validity of the approach.

  20. Perfectly Matched Layers versus discrete transparent boundary conditions in quantum device simulations

    SciTech Connect

    Mennemann, Jan-Frederik Jüngel, Ansgar

    2014-10-15

    Discrete transparent boundary conditions (DTBC) and the Perfectly Matched Layers (PML) method for the realization of open boundary conditions in quantum device simulations are compared, based on the stationary and time-dependent Schrödinger equation. The comparison includes scattering state, wave packet, and transient scattering state simulations in one and two space dimensions. The Schrödinger equation is discretized by a second-order Crank–Nicolson method in case of DTBC. For the discretization with PML, symmetric second-, fourth-, and sixth-order spatial approximations as well as Crank–Nicolson and classical Runge–Kutta time-integration methods are employed. In two space dimensions, a ring-shaped quantum waveguide device is simulated in the stationary and transient regime. As an application, a simulation of the Aharonov–Bohm effect in this device is performed, showing the excitation of bound states localized in the ring region. The numerical experiments show that the results obtained from PML are comparable to those obtained using DTBC, while keeping the high numerical efficiency and flexibility as well as the ease of implementation of the former method. -- Highlights: •In-depth comparison between discrete transparent boundary conditions (DTBC) and PML. •First 2-D transient scattering state simulations using DTBC. •First 2-D transient scattering state simulations of the Aharonov–Bohm effect.

  1. Crosswell electromagnetic modeling from impulsive source: Optimization strategy for dispersion suppression in convolutional perfectly matched layer

    PubMed Central

    Fang, Sinan; Pan, Heping; Du, Ting; Konaté, Ahmed Amara; Deng, Chengxiang; Qin, Zhen; Guo, Bo; Peng, Ling; Ma, Huolin; Li, Gang; Zhou, Feng

    2016-01-01

    This study applied the finite-difference time-domain (FDTD) method to forward modeling of the low-frequency crosswell electromagnetic (EM) method. Specifically, we implemented impulse sources and convolutional perfectly matched layer (CPML). In the process to strengthen CPML, we observed that some dispersion was induced by the real stretch κ, together with an angular variation of the phase velocity of the transverse electric plane wave; the conclusion was that this dispersion was positively related to the real stretch and was little affected by grid interval. To suppress the dispersion in the CPML, we first derived the analytical solution for the radiation field of the magneto-dipole impulse source in the time domain. Then, a numerical simulation of CPML absorption with high-frequency pulses qualitatively amplified the dispersion laws through wave field snapshots. A numerical simulation using low-frequency pulses suggested an optimal parameter strategy for CPML from the established criteria. Based on its physical nature, the CPML method of simply warping space-time was predicted to be a promising approach to achieve ideal absorption, although it was still difficult to entirely remove the dispersion. PMID:27585538

  2. Unified perfectly matched layer for finite-difference time-domain modeling of dispersive optical materials.

    PubMed

    Udagedara, Indika; Premaratne, Malin; Rukhlenko, Ivan D; Hattori, Haroldo T; Agrawal, Govind P

    2009-11-09

    Finite-difference time-domain (FDTD) simulations of any electromagnetic problem require truncation of an often-unbounded physical region by an electromagnetically bounded region by deploying an artificial construct known as the perfectly matched layer (PML). As it is not possible to construct a universal PML that is non-reflective for different materials, PMLs that are tailored to a specific problem are required. For example, depending on the number of dispersive materials being truncated at the boundaries of a simulation region, an FDTD code may contain multiple sets of update equations for PML implementations. However, such an approach is prone to introducing coding errors. It also makes it extremely difficult to maintain and upgrade an existing FDTD code. In this paper, we solve this problem by developing a new, unified PML algorithm that can effectively truncate all types of linearly dispersive materials. The unification of the algorithm is achieved by employing a general form of the medium permittivity that includes three types of dielectric response functions, known as the Debye, Lorentz, and Drude response functions, as particular cases. We demonstrate the versatility and flexibility of the new formulation by implementing a single FDTD code to simulate absorption of electromagnetic pulse inside a medium that is adjacent to dispersive materials described by different dispersion models. The proposed algorithm can also be used for simulations of optical phenomena in metamaterials and materials exhibiting negative refractive indices.

  3. Crosswell electromagnetic modeling from impulsive source: Optimization strategy for dispersion suppression in convolutional perfectly matched layer

    NASA Astrophysics Data System (ADS)

    Fang, Sinan; Pan, Heping; Du, Ting; Konaté, Ahmed Amara; Deng, Chengxiang; Qin, Zhen; Guo, Bo; Peng, Ling; Ma, Huolin; Li, Gang; Zhou, Feng

    2016-09-01

    This study applied the finite-difference time-domain (FDTD) method to forward modeling of the low-frequency crosswell electromagnetic (EM) method. Specifically, we implemented impulse sources and convolutional perfectly matched layer (CPML). In the process to strengthen CPML, we observed that some dispersion was induced by the real stretch κ, together with an angular variation of the phase velocity of the transverse electric plane wave; the conclusion was that this dispersion was positively related to the real stretch and was little affected by grid interval. To suppress the dispersion in the CPML, we first derived the analytical solution for the radiation field of the magneto-dipole impulse source in the time domain. Then, a numerical simulation of CPML absorption with high-frequency pulses qualitatively amplified the dispersion laws through wave field snapshots. A numerical simulation using low-frequency pulses suggested an optimal parameter strategy for CPML from the established criteria. Based on its physical nature, the CPML method of simply warping space-time was predicted to be a promising approach to achieve ideal absorption, although it was still difficult to entirely remove the dispersion.

  4. Impact of Recipient and Donor Obesity Match on the Outcomes of Liver Transplantation: All Matches Are Not Perfect

    PubMed Central

    Tumin, Dmitry; Conteh, Lanla F.; Hanje, A. James; Michaels, Anthony J.; Hayes, Don; Black, Sylvester M.

    2016-01-01

    There is a paucity of literature examining recipient-donor obesity matching on liver transplantation outcomes. The United Network for Organ Sharing database was queried for first-time recipients of liver transplant whose age was ≥18 between January 2003 and September 2013. Outcomes including patient and graft survival at 30 days, 1 year, and 5 years and overall, liver retransplantation, and length of stay were compared between nonobese recipients receiving a graft from nonobese donors and obese recipient-obese donor, obese recipient-nonobese donor, and nonobese recipient-obese donor pairs. 51,556 LT recipients were identified, including 34,217 (66%) nonobese and 17,339 (34%) obese recipients. The proportions of patients receiving an allograft from an obese donor were 24% and 29%, respectively, among nonobese and obese recipients. Graft loss (HR: 1.27; 95% CI: 1.09–1.46; p = 0.002) and mortality (HR: 1.38; 95% CI: 1.16–1.65; p < 0.001) at 30 days were increased in the obese recipient-obese donor pair. However, 1-year graft (HR: 0.83; 95% CI: 0.74–0.93; p = 0.002) and patient (HR: 0.84; 95% CI: 0.74–0.95; p = 0.007) survival and overall patient (HR: 0.93; 95% CI: 0.86–1.00; p = 0.042) survival were favorable. There is evidence of recipient and donor obesity disadvantage early, but survival curves demonstrate improved long-term outcomes. It is important to consider obesity in the donor-recipient match. PMID:27688905

  5. Quantitative angle-resolved small-spot reflectance measurements on plasmonic perfect absorbers: impedance matching and disorder effects.

    PubMed

    Tittl, Andreas; Harats, Moshe G; Walter, Ramon; Yin, Xinghui; Schäferling, Martin; Liu, Na; Rapaport, Ronen; Giessen, Harald

    2014-10-28

    Plasmonic devices with absorbance close to unity have emerged as essential building blocks for a multitude of technological applications ranging from trace gas detection to infrared imaging. A crucial requirement for such elements is the angle independence of the absorptive performance. In this work, we develop theoretically and verify experimentally a quantitative model for the angular behavior of plasmonic perfect absorber structures based on an optical impedance matching picture. To achieve this, we utilize a simple and elegant k-space measurement technique to record quantitative angle-resolved reflectance measurements on various perfect absorber structures. Particularly, this method allows quantitative reflectance measurements on samples where only small areas have been nanostructured, for example, by electron-beam lithography. Combining these results with extensive numerical modeling, we find that matching of both the real and imaginary parts of the optical impedance is crucial to obtain perfect absorption over a large angular range. Furthermore, we successfully apply our model to the angular dispersion of perfect absorber geometries with disordered plasmonic elements as a favorable alternative to current array-based designs.

  6. Development of a Perfectly Matched Layer Technique for a Discontinuous-Galerkin Spectral-Element Method

    NASA Technical Reports Server (NTRS)

    Garai, Anirban; Murman, Scott M.; Madavan, Nateri K.

    2016-01-01

    used involves modeling the pressure fluctuations as acoustic waves propagating in the far-field relative to a single noise-source inside the buffer region. This approach treats vorticity-induced pressure fluctuations the same as acoustic waves. Another popular approach, often referred to as the "sponge layer," attempts to dampen the flow perturbations by introducing artificial dissipation in the buffer region. Although the artificial dissipation removes all perturbations inside the sponge layer, incoming waves are still reflected from the interface boundary between the computational domain and the sponge layer. The effect of these refkections can be somewhat mitigated by appropriately selecting the artificial dissipation strength and the extent of the sponge layer. One of the most promising variants on the buffer region approach is the Perfectly Matched Layer (PML) technique. The PML technique mitigates spurious reflections from boundaries and interfaces by dampening the perturbation modes inside the buffer region such that their eigenfunctions remain unchanged. The technique was first developed by Berenger for application to problems involving electromagnetic wave propagation. It was later extended to the linearized Euler, Euler and Navier-Stokes equations by Hu and his coauthors. The PML technique ensures the no-reflection property for all waves, irrespective of incidence angle, wavelength, and propagation direction. Although the technique requires the solution of a set of auxiliary equations, the computational overhead is easily justified since it allows smaller domain sizes and can provide better accuracy, stability, and convergence of the numerical solution. In this paper, the PML technique is developed in the context of a high-order spectral-element Discontinuous Galerkin (DG) method. The technique is compared to other approaches to treating the in flow and out flow boundary, such as those based on using characteristic boundary conditions and sponge layers. The

  7. A perfectly matched layer for fluid-solid problems: Application to ocean-acoustics simulations with solid ocean bottoms.

    PubMed

    Xie, Zhinan; Matzen, René; Cristini, Paul; Komatitsch, Dimitri; Martin, Roland

    2016-07-01

    A time-domain Legendre spectral-element method is described for full-wave simulation of ocean acoustics models, i.e., coupled fluid-solid problems in unbounded or semi-infinite domains, taking into account shear wave propagation in the ocean bottom. The technique can accommodate range-dependent and depth-dependent wave speed and density, as well as steep ocean floor topography. For truncation of the infinite domain, to efficiently absorb outgoing waves, a fluid-solid complex-frequency-shifted unsplit perfectly matched layer is introduced based on the complex coordinate stretching technique. The complex stretching is rigorously taken into account in the derivation of the fluid-solid matching condition inside the absorbing layer, which has never been done before in the time domain. Two implementations are designed: a convolutional formulation and an auxiliary differential equation formulation because the latter allows for implementation of high-order time schemes, leading to reduced numerical dispersion and dissipation, a topic of importance, in particular, in long-range ocean acoustics simulations. The method is validated for a two dimensional fluid-solid Pekeris waveguide and for a three dimensional seamount model, which shows that the technique is accurate and numerically long-time stable. Compared with widely used paraxial absorbing boundary conditions, the perfectly matched layer is significantly more efficient at absorbing both body waves and interface waves.

  8. Incident angle insensitive tunable multichannel perfect absorber consisting of nonlinear plasma and matching metamaterials

    SciTech Connect

    Kong, Xiang-kun; Liu, Shao-Bin Bian, Bo-rui; Chen, Chen; Zhang, Hai-feng

    2014-12-15

    A novel, compact, and multichannel nonreciprocal absorber through a wave tunneling mechanism in epsilon-negative and matching metamaterials is theoretically proposed. Nonreciprocal absorption properties are acquired via the coupling together of evanescent and propagating waves in an asymmetric configuration, constituted of nonlinear plasma alternated with matching metamaterial. The absorption channel number can be adjusted by changing the periodic number. Due to the positive feedback between nonlinear permittivity of plasma and the inner electric field, bistable absorption and reflection are achieved. Moreover, compared with some truncated photonic crystal or multilayered designs proposed before, our design is more compact and independent of incident angle or polarization. This kind of multilayer structure offers additional opportunities to design novel omnidirectional electromagnetic wave absorbers.

  9. Matched elastic constants for a perfect helical planar state and a fast switching time in chiral nematic liquid crystals.

    PubMed

    Yu, Meina; Zhou, Xiaochen; Jiang, Jinghua; Yang, Huai; Yang, Deng-Ke

    2016-05-11

    Chiral nematic liquid crystals possess a self-assembled helical structure and exhibit unique selective reflection in visible and infrared light regions. Their optical properties can be electrically tuned. The tuning involves the unwinding and restoring of the helical structure. We carried out an experimental study on the mechanism of the restoration of the helical structure. We constructed chiral nematic liquid crystals with variable elastic constants by doping bent-dimers and studied their impact on the restoration. With matched twist and bend elastic constants, the helical structure can be restored dramatically fast from the field-induced homeotropic state. Furthermore, defects can be eliminated to produce a perfect planar state which exhibits high selective reflection.

  10. Improving the Nephrology Match: the Path Forward.

    PubMed

    Hsu, Chi-yuan; Parker, Mark G; Ross, Michael J; Schmidt, Rebecca J; Harris, Raymond C

    2015-11-01

    The Fellowship Match process was designed to provide applicants and program directors with an opportunity to consider all their options before making decisions about post-residency training. In a Match, applicants can choose the programs that best suit their career goals, and program directors can consider all candidates before preparing a rank order list. The Match is a contract, requiring obligations of both programs and applicants to achieve success, ensure uniformity, and standardize participation.

  11. Improving The Perfect Storm: Overcoming Barriers To Climate Literacy

    NASA Astrophysics Data System (ADS)

    Tillinger, D.

    2015-12-01

    Students and scientists are trained to speak different languages. Climate science, and the geosciences more broadly, are strictly classroom topics, not subjects appropriate for casual conversation, social media, or creative projects. When students are aware of climate change through the mainstream media, it is nearly always in a political or technological context rather than a scientific one. However, given the opportunity, students are perfectly capable of not only understanding the science behind climate change, but communicating it to their peers. At the American Museum of Natural History, a group of underprivileged high school students visited Nature's Fury: The Science of Natural Disasters to learn about volcanoes, earthquakes, and climate change impacts. They were then able to write pitches and develop trailers for scientifically accurate, but still compelling, disaster movies. Arts in Parts, a creative outreach group formed as a response to Hurricane Sandy, facilitated a workshop in which younger children made mobiles from beach debris they collected while learning about the the threat of sea level rise locally and globally. Participants in an undergraduate natural disasters class wrote guides to understanding climate change that remained factual while showing great creativity and reflecting the personality of each student. Art, humor, and popular culture are the languages that society chooses to use; scientific literacy might benefit from their inclusion.

  12. 3-D Quantum Transport Solver Based on the Perfectly Matched Layer and Spectral Element Methods for the Simulation of Semiconductor Nanodevices

    PubMed Central

    Cheng, Candong; Lee, Joon-Ho; Lim, Kim Hwa; Massoud, Hisham Z.; Liu, Qing Huo

    2007-01-01

    A 3-D quantum transport solver based on the spectral element method (SEM) and perfectly matched layer (PML) is introduced to solve the 3-D Schrödinger equation with a tensor effective mass. In this solver, the influence of the environment is replaced with the artificial PML open boundary extended beyond the contact regions of the device. These contact regions are treated as waveguides with known incident waves from waveguide mode solutions. As the transmitted wave function is treated as a total wave, there is no need to decompose it into waveguide modes, thus significantly simplifying the problem in comparison with conventional open boundary conditions. The spectral element method leads to an exponentially improving accuracy with the increase in the polynomial order and sampling points. The PML region can be designed such that less than −100 dB outgoing waves are reflected by this artificial material. The computational efficiency of the SEM solver is demonstrated by comparing the numerical and analytical results from waveguide and plane-wave examples, and its utility is illustrated by multiple-terminal devices and semiconductor nanotube devices. PMID:18037971

  13. Improved artificial bee colony algorithm based gravity matching navigation method.

    PubMed

    Gao, Wei; Zhao, Bo; Zhou, Guang Tao; Wang, Qiu Ying; Yu, Chun Yang

    2014-07-18

    Gravity matching navigation algorithm is one of the key technologies for gravity aided inertial navigation systems. With the development of intelligent algorithms, the powerful search ability of the Artificial Bee Colony (ABC) algorithm makes it possible to be applied to the gravity matching navigation field. However, existing search mechanisms of basic ABC algorithms cannot meet the need for high accuracy in gravity aided navigation. Firstly, proper modifications are proposed to improve the performance of the basic ABC algorithm. Secondly, a new search mechanism is presented in this paper which is based on an improved ABC algorithm using external speed information. At last, modified Hausdorff distance is introduced to screen the possible matching results. Both simulations and ocean experiments verify the feasibility of the method, and results show that the matching rate of the method is high enough to obtain a precise matching position.

  14. Improved electromagnetic induction processing with novel adaptive matched filter and matched subspace detection

    NASA Astrophysics Data System (ADS)

    Hayes, Charles E.; McClellan, James H.; Scott, Waymond R.; Kerr, Andrew J.

    2016-05-01

    This work introduces two advances in wide-band electromagnetic induction (EMI) processing: a novel adaptive matched filter (AMF) and matched subspace detection methods. Both advances make use of recent work with a subspace SVD approach to separating the signal, soil, and noise subspaces of the frequency measurements The proposed AMF provides a direct approach to removing the EMI self-response while improving the signal to noise ratio of the data. Unlike previous EMI adaptive downtrack filters, this new filter will not erroneously optimize the EMI soil response instead of the EMI target response because these two responses are projected into separate frequency subspaces. The EMI detection methods in this work elaborate on how the signal and noise subspaces in the frequency measurements are ideal for creating the matched subspace detection (MSD) and constant false alarm rate matched subspace detection (CFAR) metrics developed by Scharf The CFAR detection metric has been shown to be the uniformly most powerful invariant detector.

  15. Gun bore flaw image matching based on improved SIFT descriptor

    NASA Astrophysics Data System (ADS)

    Zeng, Luan; Xiong, Wei; Zhai, You

    2013-01-01

    In order to increase the operation speed and matching ability of SIFT algorithm, the SIFT descriptor and matching strategy are improved. First, a method of constructing feature descriptor based on sector area is proposed. By computing the gradients histogram of location bins which are parted into 6 sector areas, a descriptor with 48 dimensions is constituted. It can reduce the dimension of feature vector and decrease the complexity of structuring descriptor. Second, it introduce a strategy that partitions the circular region into 6 identical sector areas starting from the dominate orientation. Consequently, the computational complexity is reduced due to cancellation of rotation operation for the area. The experimental results indicate that comparing with the OpenCV SIFT arithmetic, the average matching speed of the new method increase by about 55.86%. The matching veracity can be increased even under some variation of view point, illumination, rotation, scale and out of focus. The new method got satisfied results in gun bore flaw image matching. Keywords: Metrology, Flaw image matching, Gun bore, Feature descriptor

  16. Singing Video Games May Help Improve Pitch-Matching Accuracy

    ERIC Educational Resources Information Center

    Paney, Andrew S.

    2015-01-01

    The purpose of this study was to investigate the effect of singing video games on the pitch-matching skills of undergraduate students. Popular games like "Rock Band" and "Karaoke Revolutions" rate players' singing based on the correctness of the frequency of their sung response. Players are motivated to improve their…

  17. Improvement of EUV mix-match overlay for production implementation

    NASA Astrophysics Data System (ADS)

    Park, Sarohan; Lee, ByoungHoon; Lee, Byong-Seog; Lee, Inwhan; Lim, Chang-Moon

    2016-03-01

    The improvement of overlay control in extreme ultra-violet (EUV) lithography is one of critical issues for successful mass production by using it. Especially it is important to improve the mix and match overlay or matched machine overlay (MMO) between EUV and ArF immersion tool, because EUV process will be applied to specific layers that have more competitive cost edge against ArF immersion multiple patterning with the early mass productivity of EUVL. Therefore it is necessary to consider the EUV overlay target with comparing the overlay specification of double patterning technology (DPT) and spacer patterning technology (SPT). This paper will discuss about required overlay controllability and current performance of EUV, and challenges for future improvement.

  18. Impedance matched joined drill pipe for improved acoustic transmission

    DOEpatents

    Moss, William C.

    2000-01-01

    An impedance matched jointed drill pipe for improved acoustic transmission. A passive means and method that maximizes the amplitude and minimize the temporal dispersion of acoustic signals that are sent through a drill string, for use in a measurement while drilling telemetry system. The improvement in signal transmission is accomplished by replacing the standard joints in a drill string with joints constructed of a material that is impedance matched acoustically to the end of the drill pipe to which it is connected. Provides improvement in the measurement while drilling technique which can be utilized for well logging, directional drilling, and drilling dynamics, as well as gamma-ray spectroscopy while drilling post shot boreholes, such as utilized in drilling post shot boreholes.

  19. Improving the Performance of Perfectly Matched Layers by Means of hp-Adaptivity

    DTIC Science & Technology

    2006-01-01

    of electromagnetic waves, J. Comput. Phys. 114 (1994), 185–200. [4] P. Bettess, Infinite elements, Penshaw Press, 1992. [5] J.H. Bramble and J.E...Computation, (In press), (2006). Preprint available at : http://www.math.tamu.edu/~ bramble /papers.html [6] W.C. Chew, Waves and fields in inhomogeneous media

  20. Maximizing switching current of superconductor nanowires via improved impedance matching

    NASA Astrophysics Data System (ADS)

    Zhang, Labao; Yan, Xiachao; Jia, Xiaoqing; Chen, Jian; Kang, Lin; Wu, Peiheng

    2017-02-01

    The temporary resistance triggered by phase slips will result in the switching of a superconductor nanowire to a permanent normal state, decreasing the switching current. In this letter, we propose an improved impedance matching circuit that releases the transition triggered by phase slips to the load resistor through the radio frequency (RF) port of a bias tee. The transportation properties with different load resistors indicate that the switching current decreases due to the reflection caused by impedance mismatching, and it is maximized by optimized impedance matching. Compared to the same setup without the impedance matching circuit, the switching current was increased from 8.0 μA to 12.2 μA in a niobium nitride nanowire after releasing the temporary transition triggered by phase slips. The leakage process with impedance matching outputs a voltage pulse, which enables the user to directly register the transition triggered by phase slips. The technique for maximizing the switching current has a potential practical application in superconductor devices, and the technique for counting phase slips may be applied to explore the behavior of phase slips.

  1. Multiscale real-space quantum-mechanical tight-binding calculations of electronic structure in crystals with defects using perfectly matched layers

    NASA Astrophysics Data System (ADS)

    Pourmatin, Hossein; Dayal, Kaushik

    2016-10-01

    We consider the scattering of incident plane-wave electrons from a defect in a crystal modeled by the time-harmonic Schrödinger equation. While the defect potential is localized, the far-field potential is periodic, unlike standard free-space scattering problems. Previous work on the Schrödinger equation has been almost entirely in free-space conditions; a few works on crystals have been in one-dimension. We construct absorbing boundary conditions for this problem using perfectly matched layers in a tight-binding formulation. Using the example of a point defect in graphene, we examine the efficiency and convergence of the proposed absorbing boundary condition.

  2. Perfectly Matched Layer for Galbrun's aeroacoustic equation in a cylindrical coordinates system with an axial and a swirling steady mean flow

    NASA Astrophysics Data System (ADS)

    Baccouche, Ryan; Tahar, Mabrouk Ben; Moreau, Solène

    2016-09-01

    A Perfectly Matched Layer (PML) for aeroacoustic problems using Galbrun's equation in the presence of an axial and a swirling steady mean flow is investigated in a cylindrical coordinates system. This equation is based on an Eulerian-Lagrangian description and leads to a wave equation written only in terms of the Lagrangian perturbation of the displacement. Galbrun's equation is solved by a mixed pressure-displacement Finite Element Method (FEM). To avoid instabilities in the presence of mean flow, a geometric transformation is presented. The validity and efficiency of the proposed PML formulation are established through comparisons with analytical, semi-analytical model based on Pridmore-Brown equation (extended to an axial and a swirling mean flow) and with multiple-scale models. The interest of the formulation is shown through an example of aeroacoustic radiation.

  3. Message-passing-interface-based parallel FDTD investigation on the EM scattering from a 1-D rough sea surface using uniaxial perfectly matched layer absorbing boundary.

    PubMed

    Li, J; Guo, L-X; Zeng, H; Han, X-B

    2009-06-01

    A message-passing-interface (MPI)-based parallel finite-difference time-domain (FDTD) algorithm for the electromagnetic scattering from a 1-D randomly rough sea surface is presented. The uniaxial perfectly matched layer (UPML) medium is adopted for truncation of FDTD lattices, in which the finite-difference equations can be used for the total computation domain by properly choosing the uniaxial parameters. This makes the parallel FDTD algorithm easier to implement. The parallel performance with different processors is illustrated for one sea surface realization, and the computation time of the parallel FDTD algorithm is dramatically reduced compared to a single-process implementation. Finally, some numerical results are shown, including the backscattering characteristics of sea surface for different polarization and the bistatic scattering from a sea surface with large incident angle and large wind speed.

  4. Improved phonocardiogram system based on acoustic impedance matching.

    PubMed

    Schwartz, R S; Reeves, J T; Sodal, I E; Barnes, F S

    1980-04-01

    We considered that phonocardiographic recording could be improved 1) by minimizing the acoustic impedance mismatch between the precordial tissue and transducer, 2) by optimizing the configuration of the impedance-matching medium and transducer design, and 3) by storing signals in digital form through analog-to-digital conversion of analog recordings made at the bedside. The use of an aqueous coupling medium to improve energy transmission increased signal voltage approximately 100-fold over presently used commercial devices. Further match to the crystal was achieved by a concentrating horn configuration for the aqueous medium. Measured frequency response of the device in the range 1 Hz to 1 kHz was better than two other commercially tested microphones. Inspection of comparative phonocardiograms showed more information from the new device than from the two other commercial devices. Unfiltered digitized signals, using our microphone in normal subjects, demonstrated good beat-to-beat repeatability, but analog filtering to obtain the conventional phonocardiogram showed significant loss of information. The new instrument appears to be superior to those commercial devices tested in recording heart sounds.

  5. Accuracy of pitch matching significantly improved by live voice model.

    PubMed

    Granot, Roni Y; Israel-Kolatt, Rona; Gilboa, Avi; Kolatt, Tsafrir

    2013-05-01

    Singing is, undoubtedly, the most fundamental expression of our musical capacity, yet an estimated 10-15% of Western population sings "out-of-tune (OOT)." Previous research in children and adults suggests, albeit inconsistently, that imitating a human voice can improve pitch matching. In the present study, we focus on the potentially beneficial effects of the human voice and especially the live human voice. Eighteen participants varying in their singing abilities were required to imitate in singing a set of nine ascending and descending intervals presented to them in five different randomized blocked conditions: live piano, recorded piano, live voice using optimal voice production, recorded voice using optimal voice production, and recorded voice using artificial forced voice production. Pitch and interval matching in singing were much more accurate when participants repeated sung intervals as compared with intervals played to them on the piano. The advantage of the vocal over the piano stimuli was robust and emerged clearly regardless of whether piano tones were played live and in full view or were presented via recording. Live vocal stimuli elicited higher accuracy than recorded vocal stimuli, especially when the recorded vocal stimuli were produced in a forced vocal production. Remarkably, even those who would be considered OOT singers on the basis of their performance when repeating piano tones were able to pitch match live vocal sounds, with deviations well within the range of what is considered accurate singing (M=46.0, standard deviation=39.2 cents). In fact, those participants who were most OOT gained the most from the live voice model. Results are discussed in light of the dual auditory-motor encoding of pitch analogous to that found in speech.

  6. Modeling of guided circumferential SH and Lamb-type waves in open waveguides with semi-analytical finite element and Perfectly Matched Layer method

    NASA Astrophysics Data System (ADS)

    Matuszyk, Paweł J.

    2017-01-01

    The circumferential guided waves (CGW) are of increasing interest for non-destructive inspecting pipes or other cylindrical structures. If such structures are buried underground, these modes can also deliver some valuable information about the surrounding medium or the quality of the contact between the pipe and the embedding medium. Toward this goal, the detailed knowledge of the dispersive characteristics of CGW is required; henceforth, the robust numerical method has to be established, which allows for the extensive study of the propagation of these modes under different loading conditions. Mathematically, this is the problem of the propagation of guided waves in an open waveguide. This problem differs significantly from the corresponding problem of a closed waveguide both in physical and numerical aspect. The paper presents a combination of semi-analytical finite element method with Perfectly Matched Layer technique for a class of coupled acoustics/elasticity problems with application to modeling of CGW. We discuss different aspects of our algorithm and validate the proposed approach against other established methods available in the literature. The presented numerical examples positively verify the robustness of the proposed method.

  7. An improved RANSAC algorithm for line matching on multispectral images

    NASA Astrophysics Data System (ADS)

    Wei, Lijun; Li, Yong; Yu, Hang; Xu, Liangpeng; Fan, Chunxiao

    2017-02-01

    This paper proposes a method for removing mismatched lines on multispectral images. The inaccurate detection of ending points brings a great challenge for matching lines since corresponding lines may not be integrally extracted. Due to the inaccurate detection of ending points, lines are usually mismatched with the line description. To eliminate the mismatched lines, we employ a modified RANSAC (Random Sample Consensus) consisting of two steps: (1) pick three line matches randomly and determine their intersections, which are used to calculate a transformation; (2) the best transformation is obtained by sorting the matching score of line matches and then the inliers are declared as the correct matches. Experimental results show that the proposed method can effectively remove incorrect matches on multispectral images.

  8. Improving statistical analysis of matched case-control studies.

    PubMed

    Conway, Aaron; Rolley, John X; Fulbrook, Paul; Page, Karen; Thompson, David R

    2013-06-01

    Matched case-control research designs can be useful because matching can increase power due to reduced variability between subjects. However, inappropriate statistical analysis of matched data could result in a change in the strength of association between the dependent and independent variables or a change in the significance of the findings. We sought to ascertain whether matched case-control studies published in the nursing literature utilized appropriate statistical analyses. Of 41 articles identified that met the inclusion criteria, 31 (76%) used an inappropriate statistical test for comparing data derived from case subjects and their matched controls. In response to this finding, we developed an algorithm to support decision-making regarding statistical tests for matched case-control studies.

  9. Improving the Quality of the Supply-Demand-Match in Vocational Education and Training by Anticipation and "Matching Policy"

    ERIC Educational Resources Information Center

    Lassnigg, Lorenz

    2008-01-01

    This article discusses the implications of a framework to improve matching supply and demand in VET by a policy to improve quality by using anticipation and foresight approaches. Analysis of the Austrian anticipation system identified some basic aspects such as policy. The analysis focused on two issues: the observation and measurement of…

  10. Improved Real-Time Scan Matching Using Corner Features

    NASA Astrophysics Data System (ADS)

    Mohamed, H. A.; Moussa, A. M.; Elhabiby, M. M.; El-Sheimy, N.; Sesay, Abu B.

    2016-06-01

    The automation of unmanned vehicle operation has gained a lot of research attention, in the last few years, because of its numerous applications. The vehicle localization is more challenging in indoor environments where absolute positioning measurements (e.g. GPS) are typically unavailable. Laser range finders are among the most widely used sensors that help the unmanned vehicles to localize themselves in indoor environments. Typically, automatic real-time matching of the successive scans is performed either explicitly or implicitly by any localization approach that utilizes laser range finders. Many accustomed approaches such as Iterative Closest Point (ICP), Iterative Matching Range Point (IMRP), Iterative Dual Correspondence (IDC), and Polar Scan Matching (PSM) handles the scan matching problem in an iterative fashion which significantly affects the time consumption. Furthermore, the solution convergence is not guaranteed especially in cases of sharp maneuvers or fast movement. This paper proposes an automated real-time scan matching algorithm where the matching process is initialized using the detected corners. This initialization step aims to increase the convergence probability and to limit the number of iterations needed to reach convergence. The corner detection is preceded by line extraction from the laser scans. To evaluate the probability of line availability in indoor environments, various data sets, offered by different research groups, have been tested and the mean numbers of extracted lines per scan for these data sets are ranging from 4.10 to 8.86 lines of more than 7 points. The set of all intersections between extracted lines are detected as corners regardless of the physical intersection of these line segments in the scan. To account for the uncertainties of the detected corners, the covariance of the corners is estimated using the extracted lines variances. The detected corners are used to estimate the transformation parameters between the

  11. Improved Feature Matching for Mobile Devices with IMU.

    PubMed

    Masiero, Andrea; Vettore, Antonio

    2016-08-05

    Thanks to the recent diffusion of low-cost high-resolution digital cameras and to the development of mostly automated procedures for image-based 3D reconstruction, the popularity of photogrammetry for environment surveys is constantly increasing in the last years. Automatic feature matching is an important step in order to successfully complete the photogrammetric 3D reconstruction: this step is the fundamental basis for the subsequent estimation of the geometry of the scene. This paper reconsiders the feature matching problem when dealing with smart mobile devices (e.g., when using the standard camera embedded in a smartphone as imaging sensor). More specifically, this paper aims at exploiting the information on camera movements provided by the inertial navigation system (INS) in order to make the feature matching step more robust and, possibly, computationally more efficient. First, a revised version of the affine scale-invariant feature transform (ASIFT) is considered: this version reduces the computational complexity of the original ASIFT, while still ensuring an increase of correct feature matches with respect to the SIFT. Furthermore, a new two-step procedure for the estimation of the essential matrix E (and the camera pose) is proposed in order to increase its estimation robustness and computational efficiency.

  12. Improved Feature Matching for Mobile Devices with IMU

    PubMed Central

    Masiero, Andrea; Vettore, Antonio

    2016-01-01

    Thanks to the recent diffusion of low-cost high-resolution digital cameras and to the development of mostly automated procedures for image-based 3D reconstruction, the popularity of photogrammetry for environment surveys is constantly increasing in the last years. Automatic feature matching is an important step in order to successfully complete the photogrammetric 3D reconstruction: this step is the fundamental basis for the subsequent estimation of the geometry of the scene. This paper reconsiders the feature matching problem when dealing with smart mobile devices (e.g., when using the standard camera embedded in a smartphone as imaging sensor). More specifically, this paper aims at exploiting the information on camera movements provided by the inertial navigation system (INS) in order to make the feature matching step more robust and, possibly, computationally more efficient. First, a revised version of the affine scale-invariant feature transform (ASIFT) is considered: this version reduces the computational complexity of the original ASIFT, while still ensuring an increase of correct feature matches with respect to the SIFT. Furthermore, a new two-step procedure for the estimation of the essential matrix E (and the camera pose) is proposed in order to increase its estimation robustness and computational efficiency. PMID:27527186

  13. A More Perfect Union

    ERIC Educational Resources Information Center

    DiConsiglio, John

    2012-01-01

    Alumni relations and stewardship officers have the makings of a strong partnership. Alumni relations and stewardship can be a natural fit--a perfect match even--according to Mary Jo Chiara of St. Joseph's College (SJC) in New York. Both strive to cultivate long-term relationships with constituents and build increasing levels of engagement and…

  14. Refractive index matching improves optical object detection in paper

    NASA Astrophysics Data System (ADS)

    Saarela, J. M. S.; Heikkinen, S. M.; Fabritius, T. E. J.; Haapala, A. T.; Myllylä, R. A.

    2008-05-01

    The demand for high-quality recycled pulp products has increased the need for an efficient deinking process. Assessing process efficiency via residual ink on test sheets has so far been limited to the sheet surface due to the poor transparency of paper. A refractive index matching method was studied to obtain a quantitative measure of particles within the volume of a paper sheet. In actual measurements a glass plate with etched lines from 8.5 µm to 281.1 µm wide was placed beneath the layers of cleared paper, and visible lines were counted with a microscope. Three different paper grades were tested with transparentizing agents. A diffusion theory-based regression model was used to find a correlation between transparency, paper grammage and paper thickness. These equations enable the determination of the size of an object detectable from a paper with a certain transparentizing agent or the parameters of a test sheet needed to detect objects of a known size. Anise oil was found to be the better of the two agents used, and they both had better transparentizing ability than air or water. The transparent paper grammage of the paper grades was determined for all the tested media. Paper's transparency was found to depend more on paper's thickness than grammage.

  15. A placebo-controlled, double-blind clinical trial to evaluate the efficacy of Imedeen® Time Perfection® for improving the appearance of photodamaged skin

    PubMed Central

    Stephens, Thomas J; Sigler, Monya L; Herndon, James H; Dispensa, Lisa; Le Moigne, Anne

    2016-01-01

    Objective To assess the efficacy of Imedeen Time Perfection for improving the appearance and condition of photoaged skin in healthy women. Methods This randomized, double-blind, placebo-controlled clinical trial enrolled healthy women, 35–60 years of age, with Fitzpatrick I–III and Glogau II–III skin types and mild-to-moderate facial fine lines/wrinkles. The eligible subjects were randomized to receive two tablets daily of either Imedeen Time Perfection (Imedeen) or a matching placebo for 12 weeks. Efficacy assessments included investigator rating of 16 photoaging parameters (ie, global facial appearance and 15 individual facial parameters and the average of all parameters), instrumentation (ie, ultrasound dermal density, moisture level of the stratum corneum, transepidermal water loss, cutometry), and subjects’ self-assessment. Differences in the mean change from baseline to week 12 values on these outcomes were compared between Imedeen and placebo using analysis of variance or a paired t-test. Results Seventy-four subjects with primarily Fitzpatrick skin type III (78%–79%) and Glogau type III (53%–58%) completed the study (Imedeen: n=36; placebo: n=38). The mean difference in change from baseline to week 12 for global facial assessment significantly favored Imedeen over placebo (−0.52; P=0.0017). Additionally, the mean differences in the average of all facial photoaging parameters (−0.29), mottled hyperpigmentation (−0.25), tactile laxity (−0.24), dullness (−0.47), and tactile roughness (−0.62) significantly favored Imedeen over placebo (P≤0.05). Significantly greater increases in ultrasound dermal density (+11% vs +1%; P≤0.05) and stratum corneum moisturization (+30% vs +6%; P≤0.05) were also observed for Imedeen than for placebo. There were no significant differences on other instrumental outcomes. Conclusion The results of this study suggest that Imedeen Time Perfection can positively affect the appearance of photoaged skin

  16. Using Local Matching to Improve Estimates of Program Impact: Evidence from Project STAR

    ERIC Educational Resources Information Center

    Jones, Nathan; Steiner, Peter; Cook, Tom

    2011-01-01

    In this study the authors test whether matching using intact local groups improves causal estimates over those produced using propensity score matching at the student level. Like the recent analysis of Wilde and Hollister (2007), they draw on data from Project STAR to estimate the effect of small class sizes on student achievement. They propose a…

  17. Missile placement analysis based on improved SURF feature matching algorithm

    NASA Astrophysics Data System (ADS)

    Yang, Kaida; Zhao, Wenjie; Li, Dejun; Gong, Xiran; Sheng, Qian

    2015-03-01

    The precious battle damage assessment by use of video images to analysis missile placement is a new study area. The article proposed an improved speeded up robust features algorithm named restricted speeded up robust features, which combined the combat application of TV-command-guided missiles and the characteristics of video image. Its restrictions mainly reflected in two aspects, one is to restrict extraction area of feature point; the second is to restrict the number of feature points. The process of missile placement analysis based on video image was designed and a video splicing process and random sample consensus purification were achieved. The RSURF algorithm is proved that has good realtime performance on the basis of guarantee the accuracy.

  18. Does Practice Make Perfect? Role of Training and Feedback in Improving Scientists' Presentation Skills

    NASA Astrophysics Data System (ADS)

    Tankersley, R. A.; Bourexis, P.; Kaser, J. S.

    2011-12-01

    Within the research and academic communities there is a growing interest in improving the communication skills of scientists, especially their ability to communicate the substance and importance of their research to general audiences. To address this need, we developed an intensive, two-day workshop [Presentation Boot Camp (PBC)] that focuses on presenting scientific concepts and research findings more effectively to both scientific/technical audiences and the general public. Through a series of interactive sessions, participants receive training in planning and preparing presentations that communicate messages more clearly and effectively and that have a lasting impact on the audience. Topics include: knowing and identifying the needs of the audience, highlighting big ideas and take-home messages, designing effective visuals, decoding complex concepts with diagrams, and displaying data in meaningful ways. PBC attendees also receive training in the use and application of the Presentation Skills Protocol (PSP) and associated rubric for evaluating the effectiveness of scientific presentations. The PSP was originally developed as part of a NSF Graduate Teaching Fellows in K-12 Education Program (GK-12) to assess and track the impact of the GK-12 experience on the communication skills of Graduate Teaching Fellows. The PSP focuses on eleven presentation skill sets, including organization, accuracy, relevance, message, language, equity, delivery, technology, use of time, questions, and presence. The associated rubric operationally defines each of the skill sets at three categorical levels of competence: (1) proficient, (2) developing, and (3) needs attention. The PSP may be used to (1) provide scientists with regular and consistent feedback on the quality and effectiveness of their classroom and research presentations and (2) design professional development activities and training programs that target specific presentation skills. However, our evaluation results indicate

  19. The perfect storm: Match-mismatch of bio-physical events drives larval reef fish connectivity between Pulley Ridge mesophotic reef and the Florida Keys

    NASA Astrophysics Data System (ADS)

    Vaz, Ana C.; Paris, Claire B.; Olascoaga, M. Josefina; Kourafalou, Villy H.; Kang, Heesook; Reed, John K.

    2016-08-01

    Mesophotic coral reef ecosystems are remote from coastal stressors, but are still vulnerable to over-exploitation, and remain mostly unprotected. They may be the key to coral reefs resilience, yet little is known about the pattern of larval subsidies from deeper to shallower coral reef habitats. Here we use a biophysical modeling approach to test the hypothesis that fishes from mesophotic coral reef ecosystems may replenish shallow reef populations. We aim at identifying the spatio-temporal patterns and underlying mechanisms of larval connections between Pulley Ridge, a mesophotic reef in the Gulf of Mexico hosting of a variety of shallow-water tropical fishes, and the Florida Keys reefs. A new three-dimensional (3D) polygon habitat module is developed for the open-source Connectivity Modeling System to simulate larval movement behavior of the bicolor damselfish, Stegastes partitus, in a realistic 3D representation of the coral reef habitat. Biological traits such as spawning periodicity, mortality, and vertical migration are also incorporated in the model. Virtual damselfish larvae are released daily from the Pulley Ridge at 80 m depth over 60 lunar spawning cycles and tracked until settlement within a fine resolution (~900 m) hydrodynamic model of the region. Such probabilistic simulations reveal mesophotic-shallow connections with large, yet sporadic pulses of larvae settling in the Florida Keys. Modal and spectral analyses on the spawning time of successful larvae, and on the position of the Florida Current front with respect to Pulley Ridge, demonstrate that specific physical-biological interactions modulate these "perfect storm" events. Indeed, the co-occurrence of (1) peak spawning with frontal features, and (2) cyclonic eddies with ontogenetic vertical migration, contribute to high settlement in the Florida Keys. This study demonstrates that mesophotic coral reef ecosystems can also serve as refugia for coral reef fish and suggests that they have a critical

  20. Mimicry Is Presidential: Linguistic Style Matching in Presidential Debates and Improved Polling Numbers.

    PubMed

    Romero, Daniel M; Swaab, Roderick I; Uzzi, Brian; Galinsky, Adam D

    2015-10-01

    The current research used the contexts of U.S. presidential debates and negotiations to examine whether matching the linguistic style of an opponent in a two-party exchange affects the reactions of third-party observers. Building off communication accommodation theory (CAT), interaction alignment theory (IAT), and processing fluency, we propose that language style matching (LSM) will improve subsequent third-party evaluations because matching an opponent's linguistic style reflects greater perspective taking and will make one's arguments easier to process. In contrast, research on status inferences predicts that LSM will negatively impact third-party evaluations because LSM implies followership. We conduct two studies to test these competing hypotheses. Study 1 analyzed transcripts of U.S. presidential debates between 1976 and 2012 and found that candidates who matched their opponent's linguistic style increased their standing in the polls. Study 2 demonstrated a causal relationship between LSM and third-party observer evaluations using negotiation transcripts.

  1. Using a Spanish Surname Match to Improve Identification of Hispanic Women in Medicare Administrative Data

    PubMed Central

    Wei, Iris I; Virnig, Beth A; John, Dolly A; Morgan, Robert O

    2006-01-01

    Objective To assess the effectiveness of a Spanish surname match for improving the identification of Hispanic women in Medicare administrative data in which Hispanics are historically underrepresented. Data Sources We collected self-identified race/ethnicity data (N = 2,997) from a mailed survey sent to elderly Medicare beneficiaries who resided in 11 geographic areas consisting of eight metropolitan counties and three nonmetropolitan areas (171 counties) in the fall of 2004. The 1990 Census Spanish Surname list was used to identify Hispanics in the Medicare data. In addition, we used data published on the U.S. Census Bureau website to obtain estimates of elderly Hispanics. Study Design We used self-identified race/ethnicity as the gold standard to examine the agreement with Medicare race code alone, and with Medicare race code+Spanish surname match. Additionally, we estimated the proportions of Hispanic women and men, in each of the 11 geographic areas in our survey, using the Medicare race code alone and the Medicare race code+Spanish surname match, and compared those estimates with estimates derived from U.S. Census 2000 data. Principal Findings The Spanish surname match dramatically increased the accuracy of the Medicare race code for identifying both Hispanic and white women, producing improvements comparable with those seen for men. Conclusions We recommend the addition of a proxy race code in the Medicare data using the Spanish surname match to improve the accuracy of racial/ethnic representation. PMID:16899019

  2. Sensor-Based Vibration Signal Feature Extraction Using an Improved Composite Dictionary Matching Pursuit Algorithm

    PubMed Central

    Cui, Lingli; Wu, Na; Wang, Wenjing; Kang, Chenhui

    2014-01-01

    This paper presents a new method for a composite dictionary matching pursuit algorithm, which is applied to vibration sensor signal feature extraction and fault diagnosis of a gearbox. Three advantages are highlighted in the new method. First, the composite dictionary in the algorithm has been changed from multi-atom matching to single-atom matching. Compared to non-composite dictionary single-atom matching, the original composite dictionary multi-atom matching pursuit (CD-MaMP) algorithm can achieve noise reduction in the reconstruction stage, but it cannot dramatically reduce the computational cost and improve the efficiency in the decomposition stage. Therefore, the optimized composite dictionary single-atom matching algorithm (CD-SaMP) is proposed. Second, the termination condition of iteration based on the attenuation coefficient is put forward to improve the sparsity and efficiency of the algorithm, which adjusts the parameters of the termination condition constantly in the process of decomposition to avoid noise. Third, composite dictionaries are enriched with the modulation dictionary, which is one of the important structural characteristics of gear fault signals. Meanwhile, the termination condition of iteration settings, sub-feature dictionary selections and operation efficiency between CD-MaMP and CD-SaMP are discussed, aiming at gear simulation vibration signals with noise. The simulation sensor-based vibration signal results show that the termination condition of iteration based on the attenuation coefficient enhances decomposition sparsity greatly and achieves a good effect of noise reduction. Furthermore, the modulation dictionary achieves a better matching effect compared to the Fourier dictionary, and CD-SaMP has a great advantage of sparsity and efficiency compared with the CD-MaMP. The sensor-based vibration signals measured from practical engineering gearbox analyses have further shown that the CD-SaMP decomposition and reconstruction algorithm

  3. Sensor-based vibration signal feature extraction using an improved composite dictionary matching pursuit algorithm.

    PubMed

    Cui, Lingli; Wu, Na; Wang, Wenjing; Kang, Chenhui

    2014-09-09

    This paper presents a new method for a composite dictionary matching pursuit algorithm, which is applied to vibration sensor signal feature extraction and fault diagnosis of a gearbox. Three advantages are highlighted in the new method. First, the composite dictionary in the algorithm has been changed from multi-atom matching to single-atom matching. Compared to non-composite dictionary single-atom matching, the original composite dictionary multi-atom matching pursuit (CD-MaMP) algorithm can achieve noise reduction in the reconstruction stage, but it cannot dramatically reduce the computational cost and improve the efficiency in the decomposition stage. Therefore, the optimized composite dictionary single-atom matching algorithm (CD-SaMP) is proposed. Second, the termination condition of iteration based on the attenuation coefficient is put forward to improve the sparsity and efficiency of the algorithm, which adjusts the parameters of the termination condition constantly in the process of decomposition to avoid noise. Third, composite dictionaries are enriched with the modulation dictionary, which is one of the important structural characteristics of gear fault signals. Meanwhile, the termination condition of iteration settings, sub-feature dictionary selections and operation efficiency between CD-MaMP and CD-SaMP are discussed, aiming at gear simulation vibration signals with noise. The simulation sensor-based vibration signal results show that the termination condition of iteration based on the attenuation coefficient enhances decomposition sparsity greatly and achieves a good effect of noise reduction. Furthermore, the modulation dictionary achieves a better matching effect compared to the Fourier dictionary, and CD-SaMP has a great advantage of sparsity and efficiency compared with the CD-MaMP. The sensor-based vibration signals measured from practical engineering gearbox analyses have further shown that the CD-SaMP decomposition and reconstruction algorithm

  4. Improved diagnostics by automated matching and enhancement in fluorescein angiography of the ocular fundus

    NASA Astrophysics Data System (ADS)

    Noordmans, Herke Jan; van den Biesen, Pieter; de Roode, Rowland; Verdaasdonk, Rudolf

    2008-02-01

    An interactive image matching program has been developed to help ophthalmologists in perceiving subtle differences between sequential images obtained during fluorescein angiography. In a pilot experiment, it appeared that the image matching program could effectively correct camera alignment errors. By offering simple tools like image overlay, blinking and image subtraction, differences between angiograms can be greatly enhanced and interpreted. It appeared that newly formed, leaking blood vessels could be detected at an earlier stage of the disease process using these tools. Treatment can be initiated right away, thereby preventing the patient from having additional visual loss. The matching program seems to improve the quality of fundus diagnostics but needs to be validated in future studies.

  5. Speed improvements of peptide-spectrum matching using single-instruction multiple-data instructions.

    PubMed

    Zhang, Jian; McQuillan, Ian; Wu, Fang-Xiang

    2011-10-01

    Peptide-spectrum matching is one of the most time-consuming portion of the database search method for assignment of tandem mass spectra to peptides. In this study, we develop a parallel algorithm for peptide-spectrum matching using Single-Instruction Multiple Data (SIMD) instructions. Unlike other parallel algorithms in peptide-spectrum matching, our algorithm parallelizes the computation of matches between a single spectrum and a given peptide sequence from the database. It also significantly reduces the number of comparison operations. Extra improvements are obtained by using SIMD instructions to avoid conditional branches and unnecessary memory access within the algorithm. The implementation of the developed algorithm is based on the Streaming SIMD Extensions technology that is embedded in most Intel microprocessors. Similar technology also exists in other modern microprocessors. A simulation shows that the developed algorithm achieves an 18-fold speedup over the previous version of Real-Time Peptide-Spectrum Matching algorithm [F. X. Wu et al., Rapid Commun. Mass Sepctrom. 2006, 20, 1199-1208]. Therefore, the developed algorithm can be employed to develop real-time control methods for MS/MS.

  6. An improved SIFT algorithm in the application of close-range Stereo image matching

    NASA Astrophysics Data System (ADS)

    Zhang, Xuehua; Wang, Xiaoqing; Yuan, Xiaoxiang; Wang, Shumin

    2016-11-01

    As unmanned aerial vehicle (UAV) remote sensing is applied in small area aerial photogrammetry surveying, disaster monitoring and emergency command, 3D urban construction and other fields, the image processing of UAV has become a hot topic in current research. The precise matching of UAV image is a key problem, which affects the subsequent processing precision directly, such as 3D reconstruction and automatic aerial triangulation, etc. At present, SIFT (Scale Invariant Feature Transform) algorithm proposed by DAVID G. LOWE as the main method is, is widely used in image matching, since its strong stability to image rotation, shift, scaling, and the change of illumination conditions. It has been successfully applied in target recognition, SFM (Structure from Motion), and many other fields. SIFT algorithm needs the colour images to be converted into grayscale images, detects extremum points under different scales and uses neighbourhood pixels to generate descriptor. As we all know that UAV images with rich colour information, the SIFT algorithm improved through combining with the image colour information in this paper, the experiments are conducted from matching efficiency and accuracy compared with the original SIFT algorithm. The results show that the method which proposed in this paper decreases on the efficiency, but is improved on the precision and provides a basis choice for matching method.

  7. An improved finger-vein recognition algorithm based on template matching

    NASA Astrophysics Data System (ADS)

    Liu, Yueyue; Di, Si; Jin, Jian; Huang, Daoping

    2016-10-01

    Finger-vein recognition has became the most popular biometric identify methods. The investigation on the recognition algorithms always is the key point in this field. So far, there are many applicable algorithms have been developed. However, there are still some problems in practice, such as the variance of the finger position which may lead to the image distortion and shifting; during the identification process, some matching parameters determined according to experience may also reduce the adaptability of algorithm. Focus on above mentioned problems, this paper proposes an improved finger-vein recognition algorithm based on template matching. In order to enhance the robustness of the algorithm for the image distortion, the least squares error method is adopted to correct the oblique finger. During the feature extraction, local adaptive threshold method is adopted. As regard as the matching scores, we optimized the translation preferences as well as matching distance between the input images and register images on the basis of Naoto Miura algorithm. Experimental results indicate that the proposed method can improve the robustness effectively under the finger shifting and rotation conditions.

  8. Spectral matching in Hyperion images for improved characterization of Mangrove ecosystems in southern India

    NASA Astrophysics Data System (ADS)

    Padma, S.; Sanjeevi, S.

    2014-11-01

    Mangrove ecosystem study is one of the main beneficiaries of the application of hyperspectral data and spectral matching techniques. Diversity and density of mangrove species leads to complexity of the ecosystem. Hence, species level mapping becomes difficult. Though hyperspectral images are appropriate for such a mapping, different mangrove species with closely matching spectra pose a challenge. This paper proposes a novel hyperspectral matching algorithm by integrating the stochastic Jeffries-Matusita measure (JM) and deterministic Spectral Angle Mapper (SAM) to accurately map most species of the mangrove ecosystem. The JM-SAM algorithm signifies the combination of an quantitative angle measure (SAM) and an qualitative distance measure (JM). The spectral capabilities of both the measures are orthogonally projected using tangent and sine functions to result in the combined algorithm. The developed JM-SAM algorithm is implemented to discriminate the mangrove species and the landcover classes of Pichavaram and Muthupet mangrove forests of southern India using the Hyperion datasets. The developed algorithm is extended in a supervised framework for improved classification of the Hyperion image. The reference spectra of the mangrove species and other cover types are extracted from the Hyperion image. From the values of relative spectral discriminatory probability and relative discriminatory entropy value, it can be inferred that hybrid JM-SAM matching measure results in improved discriminability than the individual SAM and JM algorithms. This performance is reflected in the classification results where the JM-SAM (TAN) and JM-SAM (SIN) matching algorithms yielded an improved accuracy of (86.25%,85%) and (88.10%, 86.96) for both the study sites.

  9. Improvement of retinal blood vessel detection by spur removal and Gaussian matched filtering compensation

    NASA Astrophysics Data System (ADS)

    Xiao, Di; Vignarajan, Janardhan; An, Dong; Tay-Kearney, Mei-Ling; Kanagasingam, Yogi

    2016-03-01

    Retinal photography is a non-invasive and well-accepted clinical diagnosis of ocular diseases. Qualitative and quantitative assessment of retinal images is crucial in ocular diseases related clinical application. In this paper, we proposed approaches for improving the quality of blood vessel detection based on our initial blood vessel detection methods. A blood vessel spur pruning method has been developed for removing the blood vessel spurs both on vessel medial lines and binary vessel masks, which are caused by artifacts and side-effect of Gaussian matched vessel enhancement. A Gaussian matched filtering compensation method has been developed for removing incorrect vessel branches in the areas of low illumination. The proposed approaches were applied and tested on the color fundus images from one publicly available database and our diabetic retinopathy screening dataset. A preliminary result has demonstrated the robustness and good performance of the proposed approaches and their potential application for improving retinal blood vessel detection.

  10. Neuroplasticity and MRI: A perfect match.

    PubMed

    Hamaide, Julie; De Groof, Geert; Van der Linden, Annemie

    2016-05-01

    Numerous studies have illustrated the benefits of physical workout and cognitive exercise on brain function and structure and, more importantly, on decelerating cognitive decline in old age and promoting functional rehabilitation following injury. Despite these behavioral observations, the exact mechanisms underlying these neuroplastic phenomena remain obscure. This gap illustrates the need for carefully designed in-depth studies using valid models and translational tools which allow to uncover the observed events up to the molecular level. We promote the use of in vivo magnetic resonance imaging (MRI) because it is a powerful translational imaging technique able to extract functional, structural, and biochemical information from the entire brain. Advanced processing techniques allow performing voxel-based analyses which are capable of detecting novel loci implicated in specific neuroplastic events beyond traditional regions-of-interest analyses. In addition, its non-invasive character sets it as currently the best global imaging tool for performing dynamic longitudinal studies on the same living subject, allowing thus exploring the effects of experience, training, treatment etc. in parallel to additional measures such as age, cognitive performance scores, hormone levels, and many others. The aim of this review is (i) to introduce how different animal models contributed to extend the knowledge on neuroplasticity in both health and disease, over different life stages and upon various experiences, and (ii) to illustrate how specific MRI techniques can be applied successfully to inform on the fundamental mechanisms underlying experience-dependent or activity-induced neuroplasticity including cognitive processes.

  11. Improved colour matching technique for fused nighttime imagery with daytime colours

    NASA Astrophysics Data System (ADS)

    Hogervorst, Maarten A.; Toet, Alexander

    2016-10-01

    Previously, we presented a method for applying daytime colours to fused nighttime (e.g., intensified and LWIR) imagery (Toet and Hogervorst, Opt.Eng. 51(1), 2012). Our colour mapping not only imparts a natural daylight appearance to multiband nighttime images but also enhances the contrast and visibility of otherwise obscured details. As a result, this colourizing method leads to increased ease of interpretation, better discrimination and identification of materials, faster reaction times and ultimately improved situational awareness (Toet e.a., Opt.Eng.53(4), 2014). A crucial step in this colouring process is the choice of a suitable colour mapping scheme. When daytime colour images and multiband sensor images of the same scene are available the colour mapping can be derived from matching image samples (i.e., by relating colour values to sensor signal intensities). When no exact matching reference images are available the colour transformation can be derived from the first-order statistical properties of the reference image and the multiband sensor image (Toet, Info. Fus. 4(3), 2003). In the current study we investigated new colour fusion schemes that combine the advantages of the both methods, using the correspondence between multiband sensor values and daytime colours (1st method) in a smooth transformation (2nd method). We designed and evaluated three new fusion schemes that focus on: i) a closer match with the daytime luminances, ii) improved saliency of hot targets and iii) improved discriminability of materials

  12. Dependability Improvement for PPM Compressed Data by Using Compression Pattern Matching

    NASA Astrophysics Data System (ADS)

    Kitakami, Masato; Okura, Toshihiro

    Data compression is popularly applied to computer systems and communication systems in order to reduce storage size and communication time, respectively. Since large data are used frequently, string matching for such data takes a long time. If the data are compressed, the time gets much longer because decompression is necessary. Long string matching time makes computer virus scan time longer and gives serious influence to the security of data. From this, CPM (Compression Pattern Matching) methods for several compression methods have been proposed. This paper proposes CPM method for PPM which achieves fast virus scan and improves dependability of the compressed data, where PPM is based on a Markov model, uses a context information, and achieves a better compression ratio than BW transform and Ziv-Lempel coding. The proposed method encodes the context information, which is generated in the compression process, and appends the encoded data at the beginning of the compressed data as a header. The proposed method uses only the header information. Computer simulation says that augmentation of the compression ratio is less than 5 percent if the order of the PPM is less than 5 and the source file size is more than 1M bytes, where order is the maximum length of the context used in PPM compression. String matching time is independent of the source file size and is very short, less than 0.3 micro seconds in the PC used for the simulation.

  13. Improving similarity-driven library design: customized matching and regioselective feature trees.

    PubMed

    Fischer, J Robert; Lessel, Uta; Rarey, Matthias

    2011-09-26

    Reduced graph descriptors, like feature trees, are frequently applied in cases where the relative arrangement of functional groups is more important than exact substructure matches. Due to their ability to deal with fragmented molecules, they are well-suited for fragment space search and library design. We recently presented LoFT, a novel focused library design approach based on feature trees. During evaluation two drawbacks of the reduced graph descriptor were discovered: First, regioisomeric substructures cannot be distinguished in feature tree mappings which results in a large information loss especially when connecting R-groups to cores. Second, the automatic matching procedure might result in undesired alignments, since the knowledge on what is considered as core by the user is not taken into account. In the following, we will present two approaches to overcome those drawbacks. The generation of the feature trees is modified, so that different arene substitution patterns can be recognized and a customized matching is introduced, allowing the user to determine the parts of the query, where the reagents are allowed to match. Subsequently we investigate the improvements on library design by reviewing the design scenarios which were already used for the evaluation of LoFT.

  14. An improved tropospheric ozone database retrieved from SCIAMACHY Limb-Nadir-Matching method

    NASA Astrophysics Data System (ADS)

    Jia, Jia; Rozanov, Alexei; Ladstätter-Weißenmayer, Annette; Ebojie, Felix; Rahpoe, Nabiz; Bötel, Stefan; Burrows, John

    2015-04-01

    Tropospheric ozone is one of the most important green-house gases and the main component of photochemical smog. It is either transported from the stratosphere or photochemically produced during pollution events in the troposphere that threaten the respiratory system. To investigate sources, transport mechanisms of tropospheric ozone in a global view, limb nadir matching (LNM) technique applied with SCIAMACHY instrument is used to retrieve tropospheric ozone. With the fact that 90% ozone is located in the stratosphere and only about 10% can be observed in the troposphere, the usage of satellite data requires highly qualified nadir and limb data. In this study we show an improvement of SCIAMACHY limb data as well as its influence on tropospheric ozone results. The limb nadir matching technique is also refined to increase the quality of the tropospheric ozone. The results are validated with ozone sonde measurements.

  15. Improved Electrical Load Match In California By Combining Solar Thermal Power Plants with Wind Farms

    SciTech Connect

    Vick, B. D.; Clark, R. N.; Mehos, M.

    2008-01-01

    will be during mid-day. Adding six hours of solar thermal storage improved the utility load match significantly in the evening and reliability was also improved. Storage improves reliability because electrical production can remain at a high level even when there are lulls in the wind or clouds decrease the solar energy striking the parabolic trough mirrors. The solar energy from Mojave Desert and wind energy in the major wind farm areas are not a good match to utility load during the winter in California, but if the number of wind farms were increased east of San Diego, then the utility renewable energy match would be improved (this is because the wind energy is highest during the winter in this area). Currently in California, wind electrical generation only contributes 1.8% of total electricity and solar electrical generation only contributes 0.2%. Combining wind farms and solar thermal power plants with storage would allow a large percentage of the electrical load in California to be met by wind and solar energy due to a better match with utility load than by either renewable resource separately.

  16. Dispersive matched filtering of ultrasonic guided waves for improved sparse array damage localization

    NASA Astrophysics Data System (ADS)

    Luppescu, Gregory C.; Dawson, Alexander J.; Michaels, Jennifer E.

    2016-02-01

    Although bulk waves have served as the industry standard in nondestructive evaluation for many years, guided waves (Lamb waves in plates) have become the focus of many current research efforts because they are able to interrogate larger areas of a structure in less time. Despite this advantage, guided waves also have characteristics that obfuscate data interpretation. The first property of guided waves that complicates analysis is their dispersive nature: their wave speed is a function of frequency. The second is that they are multimodal: they propagate as multiple symmetric and antisymmetric modes. Using pulse-compression techniques and a priori calculations of theoretical dispersion curves, the dispersive matched filter attempts to take advantage of these otherwise undesirable characteristics by maximizing the autocorrelation for only one mode, ideally increasing both the signal-to-noise ratio and time-resolution of ultrasonic guided wave measurements. In this research, the responses from broadband chirp excitations are recorded from a sparse transducer array after propagation through an aluminum plate containing no damage and simulated damage. Dispersive matched filtering is applied to the measurements and localization images are generated using the delay-and-sum method. Imaging results are compared to those obtained with narrowband tone burst excitations in terms of their ability to detect and localize the different scatterers. Results show that the dispersive matched filter notably improves the quality of the localization images.

  17. Improvement of efficiency of piezoelectric element attached to beam based on mechanical impedance matching

    NASA Astrophysics Data System (ADS)

    Yamada, Keisuke; Matsuhisa, Hiroshi; Utsuno, Hideo

    2014-01-01

    This paper describes new methods that improve the efficiency of a piezoelectric element attached to a beam based on mechanical impedance matching. Piezoelectric elements are often used to suppress bending vibration. They are also used as sensors or energy-harvesting sources. In such cases, the piezoelectric element is usually bonded onto the host structure by an adhesive bond. The efficiency of the piezoelectric element depends on the bonding location. When the efficiency is insufficient despite a good location, the size or number of piezoelectric elements is increased. However, the efficiency of the piezoelectric element is usually insufficient even if these methods are applied. In order to enhance the efficiency of the piezoelectric elements without using active methods, this paper proposes a mechanical impedance matching method that uses spacers or tuning for the size of the piezoelectric element. Because the attached piezoelectric element and host structure in this region behave as springs in parallel to the bending deformation, the stored strain energy in the piezoelectric element is maximized under the condition that their spring constants match. The proposed methods were theoretically investigated with consideration for the effects of the bonding layer, spacers, and host structure. The optimum conditions for the proposed methods were theoretically formulated, and the effectiveness of the proposed methods and theoretical analysis was verified through simulations and experiments.

  18. Improving mb:Ms discrimination using phase matched filters derived from regional group velocity tomography

    SciTech Connect

    Ford, S R; Hazler, S; Pasyanos, M E; Walter, W R

    1999-07-23

    This study reports on the ongoing investigation of surface wave group velocity dispersion across the Middle East and North Africa. Using broadband data gathered from various sources, we have measured group velocity using a multiple narrow-band filter method. To date, we have examined over 13,500 seismograms and made quality measurements for about 6500 Rayleigh and 3500 Love wave paths. A conjugate gradient method is used to perform the group velocity tomography at several periods. There is excellent agreement between short period structure and large known sedimentary features. Longer period structure is sensitive to crustal thickness, particularly the contrast between continental and oceanic regions and thicker crusts found beneath erogenic zones. We also find slow upper mantle velocities along rift systems. Correlation between the inversion results and known major tectonic features gives us confidence in our surface wave group velocities. Accurate group velocity maps can be used to construct phase matched filters. The filters can improve weak surface waves by compressing the dispersed signal. We are particularly interested in using the filters to calculate regionally determined M{sub s} measurements, which we hope can be used to extend the threshold of m{sub b}:M{sub s} discriminants to lower magnitude levels. A preliminary analysis of surface wave data processed using phase matched filters indicates a significant improvement in increasing the signal-to-noise ratio and improving magnitude estimates. Where signal-to-noise is very poor, phase matched filtering can still be useful in lowering the upper bound on M{sub s} measurements. We propose a series of tests in order to analyze the utility of phase matched filters. Goals of the study include determining at what distance and magnitude ranges we can expect to see improvement using the filters and the overall effect of the filters on discrimination capability. We also propose to look at seismic velocity models of

  19. Improving iris recognition performance using segmentation, quality enhancement, match score fusion, and indexing.

    PubMed

    Vatsa, Mayank; Singh, Richa; Noore, Afzel

    2008-08-01

    This paper proposes algorithms for iris segmentation, quality enhancement, match score fusion, and indexing to improve both the accuracy and the speed of iris recognition. A curve evolution approach is proposed to effectively segment a nonideal iris image using the modified Mumford-Shah functional. Different enhancement algorithms are concurrently applied on the segmented iris image to produce multiple enhanced versions of the iris image. A support-vector-machine-based learning algorithm selects locally enhanced regions from each globally enhanced image and combines these good-quality regions to create a single high-quality iris image. Two distinct features are extracted from the high-quality iris image. The global textural feature is extracted using the 1-D log polar Gabor transform, and the local topological feature is extracted using Euler numbers. An intelligent fusion algorithm combines the textural and topological matching scores to further improve the iris recognition performance and reduce the false rejection rate, whereas an indexing algorithm enables fast and accurate iris identification. The verification and identification performance of the proposed algorithms is validated and compared with other algorithms using the CASIA Version 3, ICE 2005, and UBIRIS iris databases.

  20. Automatic block-matching registration to improve lung tumor localization during image-guided radiotherapy

    NASA Astrophysics Data System (ADS)

    Robertson, Scott Patrick

    To improve relatively poor outcomes for locally-advanced lung cancer patients, many current efforts are dedicated to minimizing uncertainties in radiotherapy. This enables the isotoxic delivery of escalated tumor doses, leading to better local tumor control. The current dissertation specifically addresses inter-fractional uncertainties resulting from patient setup variability. An automatic block-matching registration (BMR) algorithm is implemented and evaluated for the purpose of directly localizing advanced-stage lung tumors during image-guided radiation therapy. In this algorithm, small image sub-volumes, termed "blocks", are automatically identified on the tumor surface in an initial planning computed tomography (CT) image. Each block is independently and automatically registered to daily images acquired immediately prior to each treatment fraction. To improve the accuracy and robustness of BMR, this algorithm incorporates multi-resolution pyramid registration, regularization with a median filter, and a new multiple-candidate-registrations technique. The result of block-matching is a sparse displacement vector field that models local tissue deformations near the tumor surface. The distribution of displacement vectors is aggregated to obtain the final tumor registration, corresponding to the treatment couch shift for patient setup correction. Compared to existing rigid and deformable registration algorithms, the final BMR algorithm significantly improves the overlap between target volumes from the planning CT and registered daily images. Furthermore, BMR results in the smallest treatment margins for the given study population. However, despite these improvements, large residual target localization errors were noted, indicating that purely rigid couch shifts cannot correct for all sources of inter-fractional variability. Further reductions in treatment uncertainties may require the combination of high-quality target localization and adaptive radiotherapy.

  1. Astronomical image denoising by means of improved adaptive backtracking-based matching pursuit algorithm.

    PubMed

    Liu, Qianshun; Bai, Jian; Yu, Feihong

    2014-11-10

    In an effort to improve compressive sensing and spare signal reconstruction by way of the backtracking-based adaptive orthogonal matching pursuit (BAOMP), a new sparse coding algorithm called improved adaptive backtracking-based OMP (ABOMP) is proposed in this study. Many aspects have been improved compared to the original BAOMP method, including replacing the fixed threshold with an adaptive one, adding residual feedback and support set verification, and others. Because of these ameliorations, the proposed algorithm can more precisely choose the atoms. By adding the adaptive step-size mechanism, it requires much less iteration and thus executes more efficiently. Additionally, a simple but effective contrast enhancement method is also adopted to further improve the denoising results and visual effect. By combining the IABOMP algorithm with the state-of-art dictionary learning algorithm K-SVD, the proposed algorithm achieves better denoising effects for astronomical images. Numerous experimental results show that the proposed algorithm performs successfully and effectively on Gaussian and Poisson noise removal.

  2. Near perfect optics

    SciTech Connect

    Goeke, R.; Farnsworth, A.V.; Neumann, C.C.; Sweatt, W.C.; Warren, M.E.; Weed, J.W.

    1996-06-01

    This report discusses a novel fabrication process to produce nearly perfect optics. The process utilizes vacuum deposition techniques to optimally modify polished optical substrate surfaces. The surface figure, i.e. contour of a polished optical element, is improved by differentially filling in the low spots on the surface using flux from a physical vapor deposition source through an appropriate mask. The process is expected to enable the manufacture of diffraction-limited optical systems for the UV, extreme UV, and soft X-ray spectral regions, which would have great impact on photolithography and astronomy. This same technique may also reduce the fabrication cost of visible region optics with aspheric surfaces.

  3. An Improved Algorithm of Congruent Matching Cells (CMC) Method for Firearm Evidence Identifications

    PubMed Central

    Tong, Mingsi; Song, John; Chu, Wei

    2015-01-01

    The Congruent Matching Cells (CMC) method was invented at the National Institute of Standards and Technology (NIST) for firearm evidence identifications. The CMC method divides the measured image of a surface area, such as a breech face impression from a fired cartridge case, into small correlation cells and uses four identification parameters to identify correlated cell pairs originating from the same firearm. The CMC method was validated by identification tests using both 3D topography images and optical images captured from breech face impressions of 40 cartridge cases fired from a pistol with 10 consecutively manufactured slides. In this paper, we discuss the processing of the cell correlations and propose an improved algorithm of the CMC method which takes advantage of the cell correlations at a common initial phase angle and combines the forward and backward correlations to improve the identification capability. The improved algorithm is tested by 780 pairwise correlations using the same optical images and 3D topography images as the initial validation. PMID:26958441

  4. Fingerprint identification using SIFT-based minutia descriptors and improved all descriptor-pair matching.

    PubMed

    Zhou, Ru; Zhong, Dexing; Han, Jiuqiang

    2013-03-06

    The performance of conventional minutiae-based fingerprint authentication algorithms degrades significantly when dealing with low quality fingerprints with lots of cuts or scratches. A similar degradation of the minutiae-based algorithms is observed when small overlapping areas appear because of the quite narrow width of the sensors. Based on the detection of minutiae, Scale Invariant Feature Transformation (SIFT) descriptors are employed to fulfill verification tasks in the above difficult scenarios. However, the original SIFT algorithm is not suitable for fingerprint because of: (1) the similar patterns of parallel ridges; and (2) high computational resource consumption. To enhance the efficiency and effectiveness of the algorithm for fingerprint verification, we propose a SIFT-based Minutia Descriptor (SMD) to improve the SIFT algorithm through image processing, descriptor extraction and matcher. A two-step fast matcher, named improved All Descriptor-Pair Matching (iADM), is also proposed to implement the 1:N verifications in real-time. Fingerprint Identification using SMD and iADM (FISiA) achieved a significant improvement with respect to accuracy in representative databases compared with the conventional minutiae-based method. The speed of FISiA also can meet real-time requirements.

  5. Improving acoustic streaming effects in fluidic systems by matching SU-8 and polydimethylsiloxane layers.

    PubMed

    Catarino, S O; Minas, G; Miranda, J M

    2016-07-01

    This paper reports the use of acoustic waves for promoting and improving streaming in tridimensional polymethylmethacrylate (PMMA) cuvettes of 15mm width×14mm height×2.5mm thickness. The acoustic waves are generated by a 28μm thick poly(vinylidene fluoride) - PVDF - piezoelectric transducer in its β phase, actuated at its resonance frequency: 40MHz. The acoustic transmission properties of two materials - SU-8 and polydimethylsiloxane (PDMS) - were numerically compared. It was concluded that PDMS inhibits, while SU-8 allows, the transmission of the acoustic waves to the propagation medium. Therefore, by simulating the acoustic transmission properties of different materials, it is possible to preview the acoustic behavior in the fluidic system, which allows the optimization of the best layout design, saving costs and time. This work also presents a comparison between numerical and experimental results of acoustic streaming obtained with that β-PVDF transducer in the movement and in the formation of fluid recirculation in tridimensional closed domains. Differences between the numerical and experimental results are credited to the high sensitivity of acoustic streaming to the experimental conditions and to limitations of the numerical method. The reported study contributes for the improvement of simulation models that can be extremely useful for predicting the acoustic effects of new materials in fluidic devices, as well as for optimizing the transducers and matching layers positioning in a fluidic structure.

  6. An Improved Map-Matching Technique Based on the Fréchet Distance Approach for Pedestrian Navigation Services

    PubMed Central

    Bang, Yoonsik; Kim, Jiyoung; Yu, Kiyun

    2016-01-01

    Wearable and smartphone technology innovations have propelled the growth of Pedestrian Navigation Services (PNS). PNS need a map-matching process to project a user’s locations onto maps. Many map-matching techniques have been developed for vehicle navigation services. These techniques are inappropriate for PNS because pedestrians move, stop, and turn in different ways compared to vehicles. In addition, the base map data for pedestrians are more complicated than for vehicles. This article proposes a new map-matching method for locating Global Positioning System (GPS) trajectories of pedestrians onto road network datasets. The theory underlying this approach is based on the Fréchet distance, one of the measures of geometric similarity between two curves. The Fréchet distance approach can provide reasonable matching results because two linear trajectories are parameterized with the time variable. Then we improved the method to be adaptive to the positional error of the GPS signal. We used an adaptation coefficient to adjust the search range for every input signal, based on the assumption of auto-correlation between consecutive GPS points. To reduce errors in matching, the reliability index was evaluated in real time for each match. To test the proposed map-matching method, we applied it to GPS trajectories of pedestrians and the road network data. We then assessed the performance by comparing the results with reference datasets. Our proposed method performed better with test data when compared to a conventional map-matching technique for vehicles. PMID:27782091

  7. Just Perfect, Part 2

    ERIC Educational Resources Information Center

    Scott, Paul

    2007-01-01

    In "Just Perfect: Part 1," the author defined a perfect number N to be one for which the sum of the divisors d (1 less than or equal to d less than N) is N. He gave the first few perfect numbers, starting with those known by the early Greeks. In this article, the author provides an extended list of perfect numbers, with some comments about their…

  8. Making a Good Match: How Schools and External Service Providers Negotiate Needs and Services in Support of School Improvement

    ERIC Educational Resources Information Center

    Vixie Sandy, Mary

    2013-01-01

    This study investigated a problem facing policy makers, education leaders, and external providers of service that support or facilitate school-based change designed to improve teaching and learning: How to match school needs with providers' services in ways that maximize school improvement. A growing number of organizations provide service to…

  9. Jeffries Matusita based mixed-measure for improved spectral matching in hyperspectral image analysis

    NASA Astrophysics Data System (ADS)

    Padma, S.; Sanjeevi, S.

    2014-10-01

    This paper proposes a novel hyperspectral matching technique by integrating the Jeffries-Matusita measure (JM) and the Spectral Angle Mapper (SAM) algorithm. The deterministic Spectral Angle Mapper and stochastic Jeffries-Matusita measure are orthogonally projected using the sine and tangent functions to increase their spectral ability. The developed JM-SAM algorithm is implemented in effectively discriminating the landcover classes and cover types in the hyperspectral images acquired by PROBA/CHRIS and EO-1 Hyperion sensors. The reference spectra for different land-cover classes were derived from each of these images. The performance of the proposed measure is compared with the performance of the individual SAM and JM approaches. From the values of the relative spectral discriminatory probability (RSDPB) and relative discriminatory entropy value (RSDE), it is inferred that the hybrid JM-SAM approach results in a high spectral discriminability than the SAM and JM measures. Besides, the use of the improved JM-SAM algorithm for supervised classification of the images results in 92.9% and 91.47% accuracy compared to 73.13%, 79.41%, and 85.69% of minimum-distance, SAM and JM measures. It is also inferred that the increased spectral discriminability of JM-SAM measure is contributed by the JM distance. Further, it is seen that the proposed JM-SAM measure is compatible with varying spectral resolutions of PROBA/CHRIS (62 bands) and Hyperion (242 bands).

  10. SU-E-T-622: Identification and Improvement of Patients Eligible for Dose Escalation with Matched Plans

    SciTech Connect

    Bush, K; Holcombe, C; Kapp, D; Buyyounouski, M; Hancock, S; Xing, L; Atwood, T; King, M

    2014-06-15

    Purpose: Radiation-therapy dose-escalation beyond 80Gy may improve tumor control rates for patients with localized prostate cancer. Since toxicity remains a concern, treatment planners must achieve dose-escalation while still adhering to dose-constraints for surrounding structures. Patientmatching is a machine-learning technique that identifies prior patients that dosimetrically match DVH parameters of target volumes and critical structures prior to actual treatment planning. We evaluated the feasibility of patient-matching in (1)identifying candidates for safe dose-escalation; and (2)improving DVH parameters for critical structures in actual dose-escalated plans. Methods: We analyzed DVH parameters from 319 historical treatment plans to determine which plans could achieve dose-escalation (8640cGy) without exceeding Zelefsky dose-constraints (rectal and bladder V47Gy<53%, and V75.6Gy<30%, max-point dose to rectum of 8550cGy, max dose to PTV< 9504cGy). We then estimated the percentage of cases that could achieve safe dose-escalation using software that enables patient matching (QuickMatch, Siris Medical, Mountain View, CA). We then replanned a case that had violated DVH constraints with DVH parameters from patient matching, in order to determine whether this previously unacceptable plan could be made eligible with this automated technique. Results: Patient-matching improved the percentage of patients eligible for dose-escalation from 40% to 63% (p=4.7e-4, t-test). Using a commercial optimizer augmented with patient-matching, we demonstrated a case where patient-matching improved the toxicity-profile such that dose-escalation would have been possible; this plan was rapidly achieved using patientmatching software. In this patient, all lower-dose constraints were met with both the denovo and patient-matching plan. In the patient-matching plan, maximum dose to the rectum was 8385cGy, while the denovo plan failed to meet the maximum rectal constraint at 8571c

  11. An improved earthquake catalogue in the Marmara Sea region, Turkey, using massive template matching

    NASA Astrophysics Data System (ADS)

    Matrullo, Emanuela; Lengliné, Olivier; Schmittbuhl, Jean; Karabulut, Hayrullah; Bouchon, Michel

    2016-04-01

    After the 1999 Izmit earthquake, the Main Marmara Fault (MMF) represents a 150 km unruptured segment of the North Anatolian Fault located below the Marmara Sea. One of the principal issue for seismic hazard assessment in the region is to know if the MMF is totally or partially locked and where the nucleation of the major forthcoming event is going to take place. The area is actually one of the best-instrumented fault systems in Europe. Since year 2007, various seismic networks both broadband, short period and OBS stations were deployed in order to monitor continuously the seismicity along the MMF and the related fault systems. A recent analysis of the seismicity recorded during the 2007-2012 period has provided new insights on the recent evolution of this important regional seismic gap. This analysis was based on events detected with STA/LTA procedure and manually picked P and S wave arrivals times (Schmittbuhl et al., 2015). In order to extend the level of details and to fully take advantage of the dense seismic network we improved the seismic catalog using an automatic earthquake detection technique based on a template matching approach. This approach uses known earthquake seismic signals in order to detect newer events similar to the tested one from waveform cross-correlation. To set-up the methodology and verify the accuracy and the robustness of the results, we initially focused in the eastern part of the Marmara Sea (Cinarcik basin) and compared new detection with those manually identified. Through the massive analysis of cross-correlation based on the template scanning of the continuous recordings, we construct a refined catalog of earthquakes for the Marmara Sea in 2007-2014 period. Our improved earthquake catalog will provide an effective tool to improve the catalog completeness, to monitor and study the fine details of the time-space distribution of events, to characterize the repeating earthquake source processes and to understand the mechanical state of

  12. Improved electrical load match in California by combining solar thermal power plants with wind farms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability of wind and solar electrical energy generation to match the current utility electrical load in California was analyzed. We compared the renewable electrical generation and the utility load in California using actual hourly wind farm data at two different locations and predicted hourly p...

  13. Misleading Cues Improve Developmental Assessment of Working Memory Capacity: The Color Matching Tasks

    ERIC Educational Resources Information Center

    Arsalidou, Marie; Pascual-Leone, Juan; Johnson, Janice

    2010-01-01

    The theory of constructive operators was used as a framework to design two versions of a paradigm (color matching task, CMT) in which items are parametrically ordered in difficulty, and differ only contextually. Items in CMT-Balloon are facilitating, whereas items in CMT-Clown contain misleading cues. Participants of ages 7-14 years and adults (N…

  14. Caffeine-containing energy drink improves physical performance of elite rugby players during a simulated match.

    PubMed

    Del Coso, Juan; Ramírez, Juan A; Muñoz, Gloria; Portillo, Javier; Gonzalez-Millán, Cristina; Muñoz, Víctor; Barbero-Álvarez, José C; Muñoz-Guerra, Jesús

    2013-04-01

    The purpose of this study was to investigate the effectiveness of a caffeine-containing energy drink in enhancing rugby players' physical performance during a simulated match. A second purpose was to determine the urinary caffeine excretion derived from the energy drink intake. In a randomized and counterbalanced order, 26 elite rugby players (mean ± SD for age and body mass, 25 ± 2 y and 93 ± 15 kg) played 2 simulated rugby games (2 × 30 min) 60 min after ingesting (i) 3 mg of caffeine per kilogram of body mass in the form of an energy drink (Fure, ProEnergetics) or (ii) the same drink without caffeine (placebo). During the matches, the individual running distance and the instantaneous speed were measured, and the number of running actions above 20 km·h(-1) (i.e., sprints) were determined, using global positioning system devices. The number of impacts above 5 g during the matches was determined by accelerometry. The ingestion of the energy drink, compared with the placebo, increased the total distance covered during the match (4749 ± 589 vs 5139 ± 475 m, p < 0.05), the running distance covered at more than 20 km·h(-1) (184 ± 38 vs 208 ± 38 m, p < 0.05), and the number of sprints (10 ± 7 vs 12 ± 7, p < 0.05). The ingestion of the energy drink also resulted in a greater overall number of impacts (481 ± 352 vs 641 ± 366, p < 0.05) and a higher postexercise urine caffeine concentration (0.1 ± 0.1 vs 2.4 ± 0.9 μg·mL(-1), p < 0.05). The use of an energy drink with a caffeine dose equivalent to 3 mg·kg(-1) considerably enhanced the movement patterns of rugby players during a simulated match.

  15. Never Perfect Enough

    ERIC Educational Resources Information Center

    Landphair, Juliette

    2007-01-01

    What exactly is perfect? Students describe perfection as a combination of characteristics valued by their peer culture: intelligence, thin and fit physical appearance, social poise. As students chug through their daily lives--morning classes, organization meetings, club sports practice or the gym, dinner, another class, more meetings, library,…

  16. Perfect embezzlement of entanglement

    NASA Astrophysics Data System (ADS)

    Cleve, Richard; Liu, Li; Paulsen, Vern I.

    2017-01-01

    Van Dam and Hayden introduced a concept commonly referred to as embezzlement, where, for any entangled quantum state ϕ, there is an entangled catalyst state ψ, from which a high fidelity approximation of ϕ ⊗ ψ can be produced using only local operations. We investigate a version of this where the embezzlement is perfect (i.e., the fidelity is 1). We prove that perfect embezzlement is impossible in a tensor product framework, even with infinite-dimensional Hilbert spaces and infinite entanglement entropy. Then we prove that perfect embezzlement is possible in a commuting operator framework. We prove this using the theory of C*-algebras and we also provide an explicit construction. Next, we apply our results to analyze perfect versions of a nonlocal game introduced by Regev and Vidick. Finally, we analyze the structure of perfect embezzlement protocols in the commuting operator model, showing that they require infinite-dimensional Hilbert spaces.

  17. Adding Boolean-Quality Control to Best-Match Searching via an Improved User Interface

    DTIC Science & Technology

    2000-05-01

    its actual relevance. The same cannot be said of a best-match system. For example, with the query “ Monarch ” AND “ butterfly ” , a Boolean system will...this to giving the roughly-analogous query “ Monarch butterfly ” to a probabilistic system. Not only is the system likely to retrieve documents that...discuss either queens and kings, or butterflies in general, without mentioning Monarch 5/31/00, 2:03 PM 4 butterflies ; but— much worse— it stands a good

  18. Application of Template Matching for Improving Classification of Urban Railroad Point Clouds

    PubMed Central

    Arastounia, Mostafa; Oude Elberink, Sander

    2016-01-01

    This study develops an integrated data-driven and model-driven approach (template matching) that clusters the urban railroad point clouds into three classes of rail track, contact cable, and catenary cable. The employed dataset covers 630 m of the Dutch urban railroad corridors in which there are four rail tracks, two contact cables, and two catenary cables. The dataset includes only geometrical information (three dimensional (3D) coordinates of the points) with no intensity data and no RGB data. The obtained results indicate that all objects of interest are successfully classified at the object level with no false positives and no false negatives. The results also show that an average 97.3% precision and an average 97.7% accuracy at the point cloud level are achieved. The high precision and high accuracy of the rail track classification (both greater than 96%) at the point cloud level stems from the great impact of the employed template matching method on excluding the false positives. The cables also achieve quite high average precision (96.8%) and accuracy (98.4%) due to their high sampling and isolated position in the railroad corridor. PMID:27973452

  19. Application of Template Matching for Improving Classification of Urban Railroad Point Clouds.

    PubMed

    Arastounia, Mostafa; Oude Elberink, Sander

    2016-12-12

    This study develops an integrated data-driven and model-driven approach (template matching) that clusters the urban railroad point clouds into three classes of rail track, contact cable, and catenary cable. The employed dataset covers 630 m of the Dutch urban railroad corridors in which there are four rail tracks, two contact cables, and two catenary cables. The dataset includes only geometrical information (three dimensional (3D) coordinates of the points) with no intensity data and no RGB data. The obtained results indicate that all objects of interest are successfully classified at the object level with no false positives and no false negatives. The results also show that an average 97.3% precision and an average 97.7% accuracy at the point cloud level are achieved. The high precision and high accuracy of the rail track classification (both greater than 96%) at the point cloud level stems from the great impact of the employed template matching method on excluding the false positives. The cables also achieve quite high average precision (96.8%) and accuracy (98.4%) due to their high sampling and isolated position in the railroad corridor.

  20. Can metric-based approaches really improve multi-model climate projections? A perfect model framework applied to summer temperature change in France.

    NASA Astrophysics Data System (ADS)

    Boé, Julien; Terray, Laurent

    2014-05-01

    -based approach a posterior estimate of climate change, based on the synthetic observation of the metric. Finally, it is possible to compare the posterior estimate to the synthetic observation of future climate change to evaluate the skill of the method. The main objective of this presentation is to describe and apply this perfect model framework to test different methodological issues associated with non-uniform model weighting and similar metric-based approaches. The methodology presented is general, but will be applied to the specific case of summer temperature change in France, for which previous works have suggested potentially useful metrics associated with soil-atmosphere and cloud-temperature interactions. The relative performances of different simple statistical approaches to combine multiple model results based on metrics will be tested. The impact of ensemble size, observational errors, internal variability, and model similarity will be characterized. The potential improvements associated with metric-based approaches compared to the MMEM is terms of errors and uncertainties will be quantified.

  1. Assessment and improvement of mapping algorithms for non-matching meshes and geometries in computational FSI

    NASA Astrophysics Data System (ADS)

    Wang, Tianyang; Wüchner, Roland; Sicklinger, Stefan; Bletzinger, Kai-Uwe

    2016-05-01

    This paper investigates data mapping between non-matching meshes and geometries in fluid-structure interaction. Mapping algorithms for surface meshes including nearest element interpolation, the standard mortar method and the dual mortar method are studied and comparatively assessed. The inconsistency problem of mortar methods at curved edges of fluid-structure-interfaces is solved by a newly developed enforcing consistency approach, which is robust enough to handle even the case that fluid boundary facets are totally not in contact with structure boundary elements due to high fluid refinement. Besides, tests with representative geometries show that the mortar methods are suitable for conservative mapping but it is better to use the nearest element interpolation in a direct way, and moreover, the dual mortar method can give slight oscillations. This work also develops a co-rotating mapping algorithm for 1D beam elements. Its novelty lies in the ability of handling large displacements and rotations.

  2. A dynamic system matching technique for improving the accuracy of MEMS gyroscopes

    NASA Astrophysics Data System (ADS)

    Stubberud, Peter A.; Stubberud, Stephen C.; Stubberud, Allen R.

    2014-12-01

    A classical MEMS gyro transforms angular rates into electrical values through Euler's equations of angular rotation. Production models of a MEMS gyroscope will have manufacturing errors in the coefficients of the differential equations. The output signal of a production gyroscope will be corrupted by noise, with a major component of the noise due to the manufacturing errors. As is the case of the components in an analog electronic circuit, one way of controlling the variability of a subsystem is to impose extremely tight control on the manufacturing process so that the coefficient values are within some specified bounds. This can be expensive and may even be impossible as is the case in certain applications of micro-electromechanical (MEMS) sensors. In a recent paper [2], the authors introduced a method for combining the measurements from several nominally equal MEMS gyroscopes using a technique based on a concept from electronic circuit design called dynamic element matching [1]. Because the method in this paper deals with systems rather than elements, it is called a dynamic system matching technique (DSMT). The DSMT generates a single output by randomly switching the outputs of several, nominally identical, MEMS gyros in and out of the switch output. This has the effect of 'spreading the spectrum' of the noise caused by the coefficient errors generated in the manufacture of the individual gyros. A filter can then be used to eliminate that part of the spread spectrum that is outside the pass band of the gyro. A heuristic analysis in that paper argues that the DSMT can be used to control the effects of the random coefficient variations. In a follow-on paper [4], a simulation of a DSMT indicated that the heuristics were consistent. In this paper, analytic expressions of the DSMT noise are developed which confirm that the earlier conclusions are valid. These expressions include the various DSMT design parameters and, therefore, can be used as design tools for DSMT

  3. A dynamic system matching technique for improving the accuracy of MEMS gyroscopes

    SciTech Connect

    Stubberud, Peter A.; Stubberud, Stephen C.; Stubberud, Allen R.

    2014-12-10

    A classical MEMS gyro transforms angular rates into electrical values through Euler's equations of angular rotation. Production models of a MEMS gyroscope will have manufacturing errors in the coefficients of the differential equations. The output signal of a production gyroscope will be corrupted by noise, with a major component of the noise due to the manufacturing errors. As is the case of the components in an analog electronic circuit, one way of controlling the variability of a subsystem is to impose extremely tight control on the manufacturing process so that the coefficient values are within some specified bounds. This can be expensive and may even be impossible as is the case in certain applications of micro-electromechanical (MEMS) sensors. In a recent paper [2], the authors introduced a method for combining the measurements from several nominally equal MEMS gyroscopes using a technique based on a concept from electronic circuit design called dynamic element matching [1]. Because the method in this paper deals with systems rather than elements, it is called a dynamic system matching technique (DSMT). The DSMT generates a single output by randomly switching the outputs of several, nominally identical, MEMS gyros in and out of the switch output. This has the effect of 'spreading the spectrum' of the noise caused by the coefficient errors generated in the manufacture of the individual gyros. A filter can then be used to eliminate that part of the spread spectrum that is outside the pass band of the gyro. A heuristic analysis in that paper argues that the DSMT can be used to control the effects of the random coefficient variations. In a follow-on paper [4], a simulation of a DSMT indicated that the heuristics were consistent. In this paper, analytic expressions of the DSMT noise are developed which confirm that the earlier conclusions are valid. These expressions include the various DSMT design parameters and, therefore, can be used as design tools for DSMT

  4. Improving Students' Understanding of the Connections between the Concepts of Real-Gas Mixtures, Gas Ideal-Solutions, and Perfect-Gas Mixtures

    ERIC Educational Resources Information Center

    Privat, Romain; Jaubert, Jean-Noël; Moine, Edouard

    2016-01-01

    In many textbooks of chemical-engineering thermodynamics, a gas mixture obeying the fundamental law pV[subscript m] = RT is most often called ideal-gas mixture (in some rare cases, the term perfect-gas mixture can be found). These textbooks also define the fundamental concept of ideal solution which in theory, can be applied indifferently to…

  5. Use of an Improved Matching Algorithm to Select Scaffolds for Enzyme Design Based on a Complex Active Site Model

    PubMed Central

    Huang, Xiaoqiang; Xue, Jing; Lin, Min; Zhu, Yushan

    2016-01-01

    Active site preorganization helps native enzymes electrostatically stabilize the transition state better than the ground state for their primary substrates and achieve significant rate enhancement. In this report, we hypothesize that a complex active site model for active site preorganization modeling should help to create preorganized active site design and afford higher starting activities towards target reactions. Our matching algorithm ProdaMatch was improved by invoking effective pruning strategies and the native active sites for ten scaffolds in a benchmark test set were reproduced. The root-mean squared deviations between the matched transition states and those in the crystal structures were < 1.0 Å for the ten scaffolds, and the repacking calculation results showed that 91% of the hydrogen bonds within the active sites are recovered, indicating that the active sites can be preorganized based on the predicted positions of transition states. The application of the complex active site model for de novo enzyme design was evaluated by scaffold selection using a classic catalytic triad motif for the hydrolysis of p-nitrophenyl acetate. Eighty scaffolds were identified from a scaffold library with 1,491 proteins and four scaffolds were native esterase. Furthermore, enzyme design for complicated substrates was investigated for the hydrolysis of cephalexin using scaffold selection based on two different catalytic motifs. Only three scaffolds were identified from the scaffold library by virtue of the classic catalytic triad-based motif. In contrast, 40 scaffolds were identified using a more flexible, but still preorganized catalytic motif, where one scaffold corresponded to the α-amino acid ester hydrolase that catalyzes the hydrolysis and synthesis of cephalexin. Thus, the complex active site modeling approach for de novo enzyme design with the aid of the improved ProdaMatch program is a promising approach for the creation of active sites with high catalytic

  6. On Improving Analytical Models of Cosmic Reionization for Matching Numerical Simulations

    SciTech Connect

    Kaurov, Alexander A.

    2016-01-01

    The methods for studying the epoch of cosmic reionization vary from full radiative transfer simulations to purely analytical models. While numerical approaches are computationally expensive and are not suitable for generating many mock catalogs, analytical methods are based on assumptions and approximations. We explore the interconnection between both methods. First, we ask how the analytical framework of excursion set formalism can be used for statistical analysis of numerical simulations and visual representation of the morphology of ionization fronts. Second, we explore the methods of training the analytical model on a given numerical simulation. We present a new code which emerged from this study. Its main application is to match the analytical model with a numerical simulation. Then, it allows one to generate mock reionization catalogs with volumes exceeding the original simulation quickly and computationally inexpensively, meanwhile reproducing large scale statistical properties. These mock catalogs are particularly useful for CMB polarization and 21cm experiments, where large volumes are required to simulate the observed signal.

  7. On Improving Analytical Models of Cosmic Reionization for Matching Numerical Simulation

    NASA Astrophysics Data System (ADS)

    Kaurov, Alexander A.

    2016-11-01

    The methods for studying the epoch of cosmic reionization vary from full radiative transfer simulations to purely analytical models. While numerical approaches are computationally expensive and are not suitable for generating many mock catalogs, analytical methods are based on assumptions and approximations. We explore the interconnection between both methods. First, we ask how the analytical framework of excursion set formalism can be used for statistical analysis of numerical simulations and visual representation of the morphology of ionization fronts. Second, we explore the methods of training the analytical model on a given numerical simulation. We present a new code which emerged from this study. Its main application is to match the analytical model with a numerical simulation. Then, it allows one to generate mock reionization catalogs with volumes exceeding the original simulation quickly and computationally inexpensively, meanwhile reproducing large-scale statistical properties. These mock catalogs are particularly useful for cosmic microwave background polarization and 21 cm experiments, where large volumes are required to simulate the observed signal.

  8. Improving food composition data quality: Three new FAO/INFOODS guidelines on conversions, data evaluation and food matching.

    PubMed

    Charrondiere, U Ruth; Rittenschober, Doris; Nowak, Verena; Stadlmayr, Barbara; Wijesinha-Bettoni, Ramani; Haytowitz, David

    2016-02-15

    Food composition data play a key role in many sectors and the availability of quality data is critically important. Since 1984, the International Network of Food Data Systems (INFOODS) has been working towards improving food composition data quality and availability, including the development and updating of standards, guidelines and tools for food composition. FAO/INFOODS has recently published three comprehensive guidelines to improve and harmonise the compilation of data: (1) Guidelines for Food Matching, (2) Guidelines for Checking Food Composition Data prior to Publication of a User Table/Database, and (3) Guidelines for Converting Units, Denominators and Expressions. This article describes their content and development processes. Their adoption, along with additional ones planned for the future by FAO/INFOODS, should further improve the quality of published food composition data, which in turn can lead to more accurate nutrient intake estimates and more precise food labels, as well as better-targeted programs and policies.

  9. Unidirectional perfect absorber

    PubMed Central

    Jin, L.; Wang, P.; Song, Z.

    2016-01-01

    This study proposes a unidirectional perfect absorber (UPA), which we realized with a two-arm Aharonov-Bohm interferometer, that consists of a dissipative resonator side-coupled to a uniform resonator array. The UPA has reflection-less full absorption on one direction, and reflectionless full transmission on the other, with an appropriate magnetic flux and coupling, detuning, and loss of the side-coupled resonator. The magnetic flux controls the transmission, the left transmission is larger for magnetic flux less than one-half flux quantum; and the right transmission is larger for magnetic flux between one-half and one flux quantum. Besides, a perfect absorber (PA) can be realized based on the UPA, in which light waves from both sides, with arbitrary superposition of the ampli- tude and phase, are perfectly absorbed. The UPA is expected to be useful in the design of novel optical devices. PMID:27615125

  10. Unidirectional perfect absorber

    NASA Astrophysics Data System (ADS)

    Jin, L.; Wang, P.; Song, Z.

    2016-09-01

    This study proposes a unidirectional perfect absorber (UPA), which we realized with a two-arm Aharonov-Bohm interferometer, that consists of a dissipative resonator side-coupled to a uniform resonator array. The UPA has reflection-less full absorption on one direction, and reflectionless full transmission on the other, with an appropriate magnetic flux and coupling, detuning, and loss of the side-coupled resonator. The magnetic flux controls the transmission, the left transmission is larger for magnetic flux less than one-half flux quantum; and the right transmission is larger for magnetic flux between one-half and one flux quantum. Besides, a perfect absorber (PA) can be realized based on the UPA, in which light waves from both sides, with arbitrary superposition of the ampli- tude and phase, are perfectly absorbed. The UPA is expected to be useful in the design of novel optical devices.

  11. Optical object detection in paper improved by refractive index matching and mechanical treatment

    NASA Astrophysics Data System (ADS)

    Saarela, J.; Heikkinen, S.; Fabritius, T.; Myllylä, R.

    2008-06-01

    Two different paper grades were tested with a clearing agent to measure how much mechanical smoothening can improve transparency inside paper. The paper grades were newsprint and supercalendered paper. The paper furnishes of both papers were alike, but the supercalendered paper was mechanically smoothened. Anise oil was used as the clearing agent, but similar measurements were also done with air and water. Black lines 8.5 μm to 281.1 μm wide were placed behind layers of cleared paper and transparency was measured with a microscope. When anise oil was the clearing agent, supercalendering improved transparent paper grammage from 139 g/m2 to 164 g/m2. With water the improvement was from 40 g/m2 to 51 g/m2. With air the improvement was not determinable. As a conclusion, it is recommended that paper is smoothened if it needs to be studied optically. Optical coherence tomography, for example, would benefit from this treatment.

  12. The Three Perfections

    ERIC Educational Resources Information Center

    Hinshaw, Craig

    2005-01-01

    For thousands of years, the three perfections--painting, poetry, and calligraphy--have been considered the mark of an enlightened person throughout Asian cultures. Fifth-grade students learned about these three hallmarks by studying three works from the Detroit Institute of Art's Asian collection: a nineteenth-century Japanese hand scroll, a…

  13. California's Perfect Storm

    ERIC Educational Resources Information Center

    Bacon, David

    2010-01-01

    The United States today faces an economic crisis worse than any since the Great Depression of the 1930s. Nowhere is it sharper than in the nation's schools. Last year, California saw a perfect storm of protest in virtually every part of its education system. K-12 teachers built coalitions with parents and students to fight for their jobs and their…

  14. The Perfect Politician

    ERIC Educational Resources Information Center

    Berry, John N., III

    2010-01-01

    The perfect politician, the ideal political ally to a library, is often but not always an elected official. He or she is always an effective champion of "reasonable financial support," i.e., "the amount...which a thoroughly competent librarian can spend wisely." That is what J.T. Wyer, director of the New York State Library, said in his "What the…

  15. In a Perfect World

    ERIC Educational Resources Information Center

    Murray, Jeannette

    2010-01-01

    In a perfect world, all children should live at home with their family, play with the kids in their neighborhood, walk or ride the school bus to a community-based school--after affectionately kissing or hugging their parents goodbye. They should receive adequate classroom services and return home at 3 p.m. or thereabouts. They may even…

  16. The Perfect Text.

    ERIC Educational Resources Information Center

    Russo, Ruth

    1998-01-01

    A chemistry teacher describes the elements of the ideal chemistry textbook. The perfect text is focused and helps students draw a coherent whole out of the myriad fragments of information and interpretation. The text would show chemistry as the central science necessary for understanding other sciences and would also root chemistry firmly in the…

  17. Lattice-Matched InGaAs–InAlAs Core–Shell Nanowires with Improved Luminescence and Photoresponse Properties

    PubMed Central

    2015-01-01

    Core–shell nanowires (NW) have become very prominent systems for band engineered NW heterostructures that effectively suppress detrimental surface states and improve performance of related devices. This concept is particularly attractive for material systems with high intrinsic surface state densities, such as the low-bandgap In-containing group-III arsenides, however selection of inappropriate, lattice-mismatched shell materials have frequently caused undesired strain accumulation, defect formation, and modifications of the electronic band structure. Here, we demonstrate the realization of closely lattice-matched radial InGaAs–InAlAs core–shell NWs tunable over large compositional ranges [x(Ga)∼y(Al) = 0.2–0.65] via completely catalyst-free selective-area molecular beam epitaxy. On the basis of high-resolution X-ray reciprocal space maps the strain in the NW core is found to be insignificant (ε < 0.1%), which is further reflected by the absence of strain-induced spectral shifts in luminescence spectra and nearly unmodified band structure. Remarkably, the lattice-matched InAlAs shell strongly enhances the optical efficiency by up to 2 orders of magnitude, where the efficiency enhancement scales directly with increasing band offset as both Ga- and Al-contents increase. Ultimately, we fabricated vertical InGaAs−InAlAs NW/Si photovoltaic cells and show that the enhanced internal quantum efficiency is directly translated to an energy conversion efficiency that is ∼3–4 times larger as compared to an unpassivated cell. These results highlight the promising performance of lattice-matched III–V core–shell NW heterostructures with significant impact on future development of related nanophotonic and electronic devices. PMID:25922974

  18. Improving pediatric cardiac surgical care in developing countries: matching resources to needs.

    PubMed

    Dearani, Joseph A; Neirotti, Rodolfo; Kohnke, Emily J; Sinha, Kingshuk K; Cabalka, Allison K; Barnes, Roxann D; Jacobs, Jeffrey P; Stellin, Giovanni; Tchervenkov, Christo I; Cushing, John C

    2010-01-01

    This article reviews a systematic approach to the design and support of pediatric cardiac surgery programs in the developing world with the guidance and strategies of Children's HeartLink, an experienced non-government organization for more than 40 years. An algorithm with criteria for the selection of a partner site is outlined. A comprehensive education strategy from the physician to the allied health care provider is the mainstay for successful program development. In a partner program, the road to successful advancement and change depends on many factors, such as government support, hospital administration support, medical staff leadership, and a committed and motivated faculty with requisite skills, incentives, and resources. In addition to these factors, it is essential that the development effort includes considerations of environment (eg, governmental support, regulatory environment, and social structure) and health system (elements related to affordability, access, and awareness of care) that impact success. Partner programs should be willing to initiate a clinical database with the intent to analyze and critique their results to optimize quality assurance and improve outcomes.

  19. Improved three-dimensional Fourier domain optical coherence tomography by index matching in alveolar structures

    NASA Astrophysics Data System (ADS)

    Meissner, Sven; Knels, Lilla; Koch, Edmund

    2009-11-01

    Three-dimensional Fourier domain optical coherence tomography (3-D FDOCT) is used to demonstrate that perfusion fixation with a mixture of glutaraldehyde and paraformaldehyde does not alter the geometry of subpleural lung parenchyma in isolated and perfused rabbit lungs. This is confirmed by simultaneous imaging of lung parenchyma with intravital microscopy. To eliminate the diffraction index interfaces between alveolar pockets and walls, we fill the fixed lungs with ethanol by perfusing with gradually increasing concentrations. This bottom-up filling process leaves no remaining air bubbles in the alveolar structures, thus drastically improving the resolution and penetration depth of 3-D FDOCT imaging. We observe an approximately 18% increase in alveolar area after ethanol filling, likely due in large part to elimination of the air/tissue interfaces. 3-D OCT datasets acquired from ethanol-filled lungs allow segmentation of the ethanol-filled structures, which were formerly air-filled, and 3-D reconstruction of larger areas of subpleural alveolar structures. Our innovative process of filling the lungs with ethanol postperfusion fixation thus enables more accurate quantification of alveolar geometries, a critical component of modeling lung function.

  20. RHIC The Perfect Liquid

    ScienceCinema

    BNL

    2016-07-12

    Evidence to date suggests that gold-gold collisions the Relativistic Heavy Ion Collider at Brookhaven are indeed creating a new state of hot, dense matter, but one quite different and even more remarkable than had been predicted. Instead of behaving like a gas of free quarks and gluons, as was expected, the matter created in RHIC's heavy ion collisions appears to be more like a "perfect" liquid.

  1. Constrained matched filtering for extended dynamic range and improved noise rejection for Shack-Hartmann wavefront sensing.

    PubMed

    Gilles, L; Ellerbroek, B L

    2008-05-15

    We recently introduced matched filtering in the context of astronomical Shack-Hartmann wavefront sensing with elongated sodium laser beacons [Appl. Opt. 45, 6568 (2006)]. Detailed wave optics Monte Carlo simulations implementing this technique for the Thirty Meter Telescope dual conjugate adaptive optics system have, however, revealed frequent bursts of degraded closed loop residual wavefront error [Proc. SPIE 6272, 627236 (2006)]. The origin of this problem is shown to be related to laser guide star jitter on the sky that kicks the filter out of its linear dynamic range, which leads to bursts of nonlinearities that are reconstructed into higher-order wavefront aberrations, particularly coma and trifoil for radially elongated subaperture spots. An elegant reformulation of the algorithm is proposed to extend its dynamic range using a set of linear constraints while preserving its improved noise rejection and Monte Carlo performance results are reported that confirm the benefits of the method.

  2. Ultra-Perfect Sorting Scenarios

    NASA Astrophysics Data System (ADS)

    Ouangraoua, Aïda; Bergeron, Anne; Swenson, Krister M.

    Perfection has been used as a criteria to select rearrangement scenarios since 2004. However, there is a fundamental bias towards extant species in the original definition: ancestral species are not bound to perfection. Here we develop a new theory of perfection that takes an egalitarian view of species, and apply it to the complex evolution of mammal chromosome X.

  3. Localized Spectroscopy from Anatomically Matched Compartments: Improved Sensitivity and Localization for Cardiac 31P MRS in Humans

    NASA Astrophysics Data System (ADS)

    Löffler, Ralf; Sauter, Rolf; Kolem, Heinrich; Haase, Axel; von Kienlin, Markus

    1998-10-01

    Several pioneering studies have demonstrated that localized31P NMR spectroscopy of the human heart might become an important diagnostic tool in cardiology. The main limitation is due to the low sensitivity of these experiments, allowing only crude spatial resolution. We have implemented a three-dimensional version of SLOOP ("spectral localization with optimal pointspread function") on a clinical instrument. SLOOP takes advantage of all availablea prioriinformation to match the size and the shape of the sensitive volumes to the anatomical structures in the examined subject. Thus, SLOOP reduces the contamination from adjacent organs and improves the sensitivity compared to conventional techniques such as ISIS or chemical shift imaging (CSI). Initial studies were performed on six healthy volunteers at 1.5 T. The good localization properties are demonstrated by the absence of resonances from blood in the heart spectra, and by PCr-free spectra from the liver. Compared to conventional CSI, the signal-to-noise ratio of the SLOOP heart spectra was improved by approximately 30%. Taking into account the varying excitation angle in the inhomogeneous B1field of the surface coil, the SLOOP model computes the local spin saturation at every point in space. Therefore, no global saturation correction is required in the quantitative evaluation of local spectra. In this study, we found a PCr/γ-ATP ratio in the left ventricular wall of 1.90 ± 0.33 (mean ± standard deviation).

  4. Soil Respiration and Student Inquiry: A Perfect Match

    ERIC Educational Resources Information Center

    Hoyt, Catherine Marie; Wallenstein, Matthew David

    2011-01-01

    This activity explores the cycling of carbon between the atmosphere (primarily as CO[subscript 2]) and biomass in plants, animals, and microscopic organisms. Students design soil respiration experiments using a protocol that resembles current practice in soil ecology. Three methods for measuring soil respiration are presented. Student-derived…

  5. Literature Circles: A Perfect Match for Online Instruction

    ERIC Educational Resources Information Center

    Whittingham, Jeff

    2013-01-01

    This article describes the author's search for an appropriate and satisfying online teaching method. After experimenting with several methods (chat room, discussion board, student led discussion), the author reached back to his face-to-face classroom success with literature circles. This article reports the results of research conducted by the…

  6. Literacy Design Collaborative and Struggling Readers: A Perfect Match

    ERIC Educational Resources Information Center

    Southern Regional Education Board (SREB), 2014

    2014-01-01

    In Florida, middle grades students take the Florida Comprehensive Assessment Test 2.0 (FCAT 2.0) in reading and writing. In partnership with the Southern Regional Education Board (SREB), Avalon Middle School implemented the Literacy Design Collaborative (LDC) framework beginning in the 2012-2013 school year to develop literacy skills across…

  7. A Perfectly Matched Layer for Peridynamics in Two Dimensions

    DTIC Science & Technology

    2013-04-01

    family, Hx , a small, arbitrary value can be chosen as a cutoff for the kernel. Note that the cutoff has a large impact on the efficiency of the method...discretization, so it is better to use a smooth transition for φ. Here, we divide the PML region into two parts, one in which φ is a constant value , and...the other in which φ ramps up to that constant value following a Gaussian distribution. An example is shown in Figure 1, with the constant region set

  8. Improved Body Mass Index Measures Following a Middle School-Based Obesity Intervention--The MATCH Program

    ERIC Educational Resources Information Center

    Lazorick, Suzanne; Fang, Xiangming; Hardison, George T.; Crawford, Yancey

    2015-01-01

    Background: Motivating Adolescents with Technology to CHOOSE Health™ (MATCH) is an educational and behavioral intervention in seventh grade. Methods: Teachers in 2 schools delivered the MATCH curriculum, with 1 control school. Using a quasi-experimental design, outcome measures included lessons completed, body mass index (BMI), BMI z-score (zBMI),…

  9. Non-matrix Matched Glass Disk Calibration Standards Improve XRF Micronutrient Analysis of Wheat Grain across Five Laboratories in India.

    PubMed

    Guild, Georgia E; Stangoulis, James C R

    2016-01-01

    Within the HarvestPlus program there are many collaborators currently using X-Ray Fluorescence (XRF) spectroscopy to measure Fe and Zn in their target crops. In India, five HarvestPlus wheat collaborators have laboratories that conduct this analysis and their throughput has increased significantly. The benefits of using XRF are its ease of use, minimal sample preparation and high throughput analysis. The lack of commercially available calibration standards has led to a need for alternative calibration arrangements for many of the instruments. Consequently, the majority of instruments have either been installed with an electronic transfer of an original grain calibration set developed by a preferred lab, or a locally supplied calibration. Unfortunately, neither of these methods has been entirely successful. The electronic transfer is unable to account for small variations between the instruments, whereas the use of a locally provided calibration set is heavily reliant on the accuracy of the reference analysis method, which is particularly difficult to achieve when analyzing low levels of micronutrient. Consequently, we have developed a calibration method that uses non-matrix matched glass disks. Here we present the validation of this method and show this calibration approach can improve the reproducibility and accuracy of whole grain wheat analysis on 5 different XRF instruments across the HarvestPlus breeding program.

  10. Non-matrix Matched Glass Disk Calibration Standards Improve XRF Micronutrient Analysis of Wheat Grain across Five Laboratories in India

    PubMed Central

    Guild, Georgia E.; Stangoulis, James C. R.

    2016-01-01

    Within the HarvestPlus program there are many collaborators currently using X-Ray Fluorescence (XRF) spectroscopy to measure Fe and Zn in their target crops. In India, five HarvestPlus wheat collaborators have laboratories that conduct this analysis and their throughput has increased significantly. The benefits of using XRF are its ease of use, minimal sample preparation and high throughput analysis. The lack of commercially available calibration standards has led to a need for alternative calibration arrangements for many of the instruments. Consequently, the majority of instruments have either been installed with an electronic transfer of an original grain calibration set developed by a preferred lab, or a locally supplied calibration. Unfortunately, neither of these methods has been entirely successful. The electronic transfer is unable to account for small variations between the instruments, whereas the use of a locally provided calibration set is heavily reliant on the accuracy of the reference analysis method, which is particularly difficult to achieve when analyzing low levels of micronutrient. Consequently, we have developed a calibration method that uses non-matrix matched glass disks. Here we present the validation of this method and show this calibration approach can improve the reproducibility and accuracy of whole grain wheat analysis on 5 different XRF instruments across the HarvestPlus breeding program. PMID:27375644

  11. Multi-domain computerized cognitive training program improves performance of bookkeeping tasks: a matched-sampling active-controlled trial

    PubMed Central

    Lampit, Amit; Ebster, Claus; Valenzuela, Michael

    2014-01-01

    Cognitive skills are important predictors of job performance, but the extent to which computerized cognitive training (CCT) can improve job performance in healthy adults is unclear. We report, for the first time, that a CCT program aimed at attention, memory, reasoning and visuo-spatial abilities can enhance productivity in healthy younger adults on bookkeeping tasks with high relevance to real-world job performance. 44 business students (77.3% female, mean age 21.4 ± 2.6 years) were assigned to either (a) 20 h of CCT, or (b) 20 h of computerized arithmetic training (active control) by a matched sampling procedure. Both interventions were conducted over a period of 6 weeks, 3–4 1-h sessions per week. Transfer of skills to performance on a 60-min paper-based bookkeeping task was measured at three time points—baseline, after 10 h and after 20 h of training. Repeated measures ANOVA found a significant Group X Time effect on productivity (F = 7.033, df = 1.745; 73.273, p = 0.003) with a significant interaction at both the 10-h (Relative Cohen's effect size = 0.38, p = 0.014) and 20-h time points (Relative Cohen's effect size = 0.40, p = 0.003). No significant effects were found on accuracy or on Conners' Continuous Performance Test, a measure of sustained attention. The results are discussed in reference to previous findings on the relationship between brain plasticity and job performance. Generalization of results requires further study. PMID:25120510

  12. Improvement of the matching speed of AIMS for development of an automatic totally tuning system for hyperthermia treatment using a resonant cavity applicator.

    PubMed

    Shindo, Y; Kato, K; Tsuchiya, K; Hirashima, T; Suzuki, M

    2009-01-01

    In this paper, we discuss the improvement of the speed of AIMS (Automatic Impedance Matching System) to automatically make impedance matching for a re-entrant resonant cavity applicator for non-invasive deep brain tumors hyperthermia treatments. We have already discussed the effectiveness of the heating method using the AIMS, with experiments of heating agar phantoms. However, the operating time of AIMS was about 30 minutes. To develop the ATT System (Automatic Totally Tuning System) including the automatic frequency tuning system, we must improve this problem. Because, when using the ATTS, the AIMS is used repeatedly to find the resonant frequency. In order to improve the speed of impedance matching, we developed the new automatic impedance matching system program (AIMS2). In AIMS, the stepping motors were connected to the impedance matching unit's dials. These dials were turned to reduce the reflected power. AIMS consists of two phases: all range searching and detailed searching. We focused on the three factors affecting the operating speed and improved them. The first factor is the interval put between the turning of the motors and AD converter. The second factor is how the steps of the motor when operating all range searching. The third factor is the starting position of the motor when detail searching. We developed the simple ATT System (ATT-beta) based on the AIMS2. To evaluate the developed AIMS2 and ATT- beta, experiments with an agar phantom were performed. From these results, we found that the operating time of the AIMS2 is about 4 minutes, which was approximately 12% of AIMS. From ATT-beta results, it was shown that it is possible to tune frequency and automatically match impedance with the program based on the AIMS2.

  13. Searching for an Improved Spectral Match to TES and IRIS Sinus Meridiani Spectra: Coatings and Cemented Materials

    NASA Astrophysics Data System (ADS)

    Kirkland, L. E.; Herr, K. C.; Adams, P. M.

    2001-05-01

    A region on Mars within Sinus Meridiani has been interpreted as a surface partially covered by coarse-grained (gray) hematite, using spectra measured by the 1996 Global Surveyor Thermal Emission Spectrometer (TES) [Lane et al., 1999; Christensen et al., 2000]. The band strengths recorded by TES of this region are consistent with either coarse-grained hematite, or cemented poorly crystalline or cemented fine-grained hematite. The band strengths are inconsistent with unconsolidated, poorly crystalline or fine-grained hematite, including nanophase hematite dust [Christensen et al., 2000]. Currently the gray hematite interpretation is based on bands centered near 22 and 33 microns. TES also records a band centered near 18 microns that was used in early hematite interpretations [Lane et al., 1999]. However, it was noted [Kirkland et al., 1999a] that the 18 micron band is too narrow in both TES and the 1971 Mariner Mars IRIS spectra to be a good match to typical spectra of well-crystalline hematite [e.g. Salisbury et al., 1991]. The 18 micron band is near the very strong 15 micron atmospheric CO2 band, but if anything the nearby CO2 band should cause the 18 micron band to appear wider, not narrower. In addition, the higher spectral resolution of IRIS allows improved separation of the bands [Kirkland et al., 1999b]. More recent publications no longer show the TES 18 micron band [e.g. Lane et al., 2000; Christensen et al., 2000], which temporarily resolved the issue. However, we feel it is important to understand why TES and IRIS spectra exhibit an 18 micron band that is too narrow to match typical spectra of coarse-grained hematite. Smooth-surfaced cemented (e.g. ferricrete) or coated materials (e.g. desert varnish) have spectral contrast that is consistent with the observed IRIS and TES band contrast. On Mars, one possible source for cemented material or coatings would be the nanophase hematite dust. Cemented materials may occur in bulk (e.g. duricrust or ferricrete), or

  14. Brachytherapy Improves Biochemical Failure–Free Survival in Low- and Intermediate-Risk Prostate Cancer Compared With Conventionally Fractionated External Beam Radiation Therapy: A Propensity Score Matched Analysis

    SciTech Connect

    Smith, Graham D.; Pickles, Tom; Crook, Juanita; Martin, Andre-Guy; Vigneault, Eric; Cury, Fabio L.; Morris, Jim; Catton, Charles; Lukka, Himu; Warner, Andrew; Yang, Ying; Rodrigues, George

    2015-03-01

    Purpose: To compare, in a retrospective study, biochemical failure-free survival (bFFS) and overall survival (OS) in low-risk and intermediate-risk prostate cancer patients who received brachytherapy (BT) (either low-dose-rate brachytherapy [LDR-BT] or high-dose-rate brachytherapy with external beam radiation therapy [HDR-BT+EBRT]) versus external beam radiation therapy (EBRT) alone. Methods and Materials: Patient data were obtained from the ProCaRS database, which contains 7974 prostate cancer patients treated with primary radiation therapy at four Canadian cancer institutions from 1994 to 2010. Propensity score matching was used to obtain the following 3 matched cohorts with balanced baseline prognostic factors: (1) low-risk LDR-BT versus EBRT; (2) intermediate-risk LDR-BT versus EBRT; and (3) intermediate-risk HDR-BT+EBRT versus EBRT. Kaplan-Meier survival analysis was performed to compare differences in bFFS (primary endpoint) and OS in the 3 matched groups. Results: Propensity score matching created acceptable balance in the baseline prognostic factors in all matches. Final matches included 2 1:1 matches in the intermediate-risk cohorts, LDR-BT versus EBRT (total n=254) and HDR-BT+EBRT versus EBRT (total n=388), and one 4:1 match in the low-risk cohort (LDR-BT:EBRT, total n=400). Median follow-up ranged from 2.7 to 7.3 years for the 3 matched cohorts. Kaplan-Meier survival analysis showed that all BT treatment options were associated with statistically significant improvements in bFFS when compared with EBRT in all cohorts (intermediate-risk EBRT vs LDR-BT hazard ratio [HR] 4.58, P=.001; intermediate-risk EBRT vs HDR-BT+EBRT HR 2.08, P=.007; low-risk EBRT vs LDR-BT HR 2.90, P=.004). No significant difference in OS was found in all comparisons (intermediate-risk EBRT vs LDR-BT HR 1.27, P=.687; intermediate-risk EBRT vs HDR-BT+EBRT HR 1.55, P=.470; low-risk LDR-BT vs EBRT HR 1.41, P=.500). Conclusions: Propensity score matched analysis showed that BT options led

  15. Perfect anti-reflection from first principles.

    PubMed

    Kim, Kyoung-Ho; Park, Q-Han

    2013-01-01

    Reducing unwanted reflections through impedance matching, called anti-reflection, has long been an important challenge in optics and electrical engineering. Beyond trial and error optimization, however, a systematic way to realize anti-reflection is still absent. Here, we report the discovery of an analytic solution to this long standing problem. For electromagnetic waves, we find the graded permittivity and permeability that completely remove any given impedance mismatch. We demonstrate that perfect broadband anti-reflection is possible when a dispersive, graded refractive index medium is used for the impedance-matching layer. We also present a design rule for the ultra-thin anti-reflection coating which we confirm experimentally by showing the anti-reflection behavior of an exemplary λ/25-thick coating made of metamaterials. This work opens a new path to anti-reflection applications in optoelectronic device, transmission line and stealth technologies.

  16. Perfect anti-reflection from first principles

    PubMed Central

    Kim, Kyoung-Ho; Q-Han Park

    2013-01-01

    Reducing unwanted reflections through impedance matching, called anti-reflection, has long been an important challenge in optics and electrical engineering. Beyond trial and error optimization, however, a systematic way to realize anti-reflection is still absent. Here, we report the discovery of an analytic solution to this long standing problem. For electromagnetic waves, we find the graded permittivity and permeability that completely remove any given impedance mismatch. We demonstrate that perfect broadband anti-reflection is possible when a dispersive, graded refractive index medium is used for the impedance-matching layer. We also present a design rule for the ultra-thin anti-reflection coating which we confirm experimentally by showing the anti-reflection behavior of an exemplary λ/25-thick coating made of metamaterials. This work opens a new path to anti-reflection applications in optoelectronic device, transmission line and stealth technologies. PMID:23320143

  17. Matching Instructional Methods with Students Learning Preferences: A Research-Based Initiative for Improving Students' Success in Mathematics

    ERIC Educational Resources Information Center

    Nolting, Kimberly; Nolting, Paul

    2008-01-01

    Research supports the effectiveness of matching instructional methods with student learning preferences (Dunn et al., 1995; Pascarella and Terenzini, 2005). Several challenges exist, however, for mathematics departments to design classroom learning experiences that allow students to learn mathematics and learn how to study math through their…

  18. Improving Balance in Regression Discontinuity Design by Matching: Estimating the Effect of Academic Probation after the First Year of College

    ERIC Educational Resources Information Center

    Chi, Olivia L.; Dow, Aaron W.

    2014-01-01

    This study focuses on how matching, a method of preprocessing data prior to estimation and analysis, can be used to reduce imbalance between treatment and control group in regression discontinuity design. To examine the effects of academic probation on student outcomes, researchers replicate and expand upon research conducted by Lindo, Sanders,…

  19. Numerical study of an ultra-broadband near-perfect solar absorber in the visible and near-infrared region.

    PubMed

    Wu, Dong; Liu, Chang; Liu, Yumin; Yu, Li; Yu, Zhongyuan; Chen, Lei; Ma, Rui; Ye, Han

    2017-02-01

    We propose and numerically investigate a novel ultra-broadband solar absorber by applying iron in a 2D simple metamaterial structure. The proposed structure can achieve the perfect absorption above 95% covering the wavelength range from 400 to 1500 nm. The average absorption reaches 97.8% over this wavelength range. The broadband perfect absorption is caused by the excitation of localized surface plasmon resonance and propagating surface plasmon resonance. We first propose and demonstrate that the iron is obviously beneficial to achieve impedance matching between the metamaterial structure and the free space over an ultra-broad frequency band in the visible and near-infrared region, which play an extremely important role to generate an ultra-broadband perfect absorption. In order to further broaden the absorption band, we also demonstrate the perfect absorption exceeding 92% for the 400-2000 nm range by adding the number of metal-dielectric pairs and using both gold and iron simultaneously in the proposed structure. The average absorption of the improved absorber reaches 96.4% over the range of 400-2000 nm. The metamaterial absorbers using iron are very promising for many applications, which can greatly broaden the perfect absorption band in the solar spectrum and, meanwhile, can enormously reduce the cost in the actual production.

  20. Practice Doesn’t Always Make Perfect: A Qualitative Study Explaining Why a Trial of an Educational Toolkit Did Not Improve Quality of Care

    PubMed Central

    Parsons, Janet A.; Yu, Catherine H. Y.; Baker, Natalie A.; Mamdani, Muhammad M.; Bhattacharyya, Onil; Zwarenstein, Merrick; Shah, Baiju R.

    2016-01-01

    Background Diabetes is a chronic disease commonly managed by family physicians, with the most prevalent complication being cardiovascular disease (CVD). Clinical practice guidelines have been developed to support clinicians in the care of diabetic patients. We conducted a pragmatic cluster randomized controlled trial (RCT) of a printed educational toolkit aimed at improving CVD management in diabetes in primary care, and found no effect, and indeed, the possibility of some harm. We conducted a qualitative evaluation to study the strategy for guideline implementation employed in this trial, and to understand its effects. This paper focuses solely on the qualitative findings, as the RCT’s quantitative results have already been reported elsewhere. Methods and Findings All family practices in the province of Ontario had been randomized to receive the educational toolkit by mail, in either the summer of 2009 (intervention arm) or the spring of 2010 (control arm).A subset of 80 family physicians (representing approximately 10% of the practices randomized and approached, with records on 1,592 randomly selected patients with diabetes at high risk for CVD) then took part in a chart audit and reflective feedback exercise related to their own practice in comparison to the guideline recommendations. They were asked to complete two forms (one pre- and one post-audit) in order to understand their awareness of the guidelines pre-trial, their expectations regarding their individual performance pre-audit, and their reflections on their audit results. In addition, individual interviews with thirteen other family physicians were conducted. Textual data from interview transcripts and written commentary from the pre- and post-audit forms underwent qualitative descriptive analysis to identify common themes and patterns. Analysis revealed four main themes: impressions of the toolkit, awareness was not the issue, ‘it’s not me it’s my patients’, and chart audit as a more

  1. IMPROVED MOCK GALAXY CATALOGS FOR THE DEEP2 GALAXY REDSHIFT SURVEY FROM SUBHALO ABUNDANCE AND ENVIRONMENT MATCHING

    SciTech Connect

    Gerke, Brian F.; Wechsler, Risa H.; Behroozi, Peter S.; Yan, Renbin; Coil, Alison L.

    2013-09-15

    We develop empirical methods for modeling the galaxy population and populating cosmological N-body simulations with mock galaxies according to the observed properties of galaxies in survey data. We use these techniques to produce a new set of mock catalogs for the DEEP2 Galaxy Redshift Survey based on the output of the high-resolution Bolshoi simulation, as well as two other simulations with different cosmological parameters, all of which we release for public use. The mock-catalog creation technique uses subhalo abundance matching to assign galaxy luminosities to simulated dark-matter halos. It then adds color information to the resulting mock galaxies in a manner that depends on the local galaxy density, in order to reproduce the measured color-environment relation in the data. In the course of constructing the catalogs, we test various models for including scatter in the relation between halo mass and galaxy luminosity, within the abundance-matching framework. We find that there is no constant-scatter model that can simultaneously reproduce both the luminosity function and the autocorrelation function of DEEP2. This result has implications for galaxy-formation theory, and it restricts the range of contexts in which the mock catalogs can be usefully applied. Nevertheless, careful comparisons show that our new mock catalogs accurately reproduce a wide range of the other properties of the DEEP2 catalog, suggesting that they can be used to gain a detailed understanding of various selection effects in DEEP2.

  2. Infrared perfect absorber based on nanowire metamaterial cavities.

    PubMed

    He, Yingran; Deng, Huixu; Jiao, Xiangyang; He, Sailing; Gao, Jie; Yang, Xiaodong

    2013-04-01

    An infrared perfect absorber based on a gold nanowire metamaterial cavities array on a gold ground plane is designed. The metamaterial made of gold nanowires embedded in an alumina host exhibits an effective permittivity with strong anisotropy, which supports cavity resonant modes of both electric dipole and magnetic dipole. The impedance of the cavity modes matches the incident plane wave in free space, leading to nearly perfect light absorption. The incident optical energy is efficiently converted into heat so that the local temperature of the absorber will increase. Results show that the designed absorber is polarization-insensitive and nearly omnidirectional for the incident angle.

  3. Interference theory of metamaterial perfect absorbers.

    PubMed

    Chen, Hou-Tong

    2012-03-26

    The impedance matching to free space in metamaterial perfect absorbers has been believed to involve and rely on magnetic resonant response, with direct evidence provided by the anti-parallel surface currents in the metal structures. Here I present a different theoretical interpretation based on interference, which shows that the two layers of metal structures in metamaterial absorbers are linked only by multiple reflections with negligible near-field interactions or magnetic resonances. This is further supported by the out-of-phase surface currents derived at the interfaces of resonator array and ground plane through multiple reflections and superpositions. The theory developed here explains all features observed in narrowband metamaterial absorbers and therefore provides a profound understanding of the underlying physics.

  4. Magnetically tunable metamaterial perfect absorber

    NASA Astrophysics Data System (ADS)

    Lei, Ming; Feng, Ningyue; Wang, Qingmin; Hao, Yanan; Huang, Shanguo; Bi, Ke

    2016-06-01

    A magnetically tunable metamaterial perfect absorber (MPA) based on ferromagnetic resonance is experimentally and numerically demonstrated. The ferrite-based MPA is composed of an array of ferrite rods and a metallic ground plane. Frequency dependent absorption of the ferrite-based MPA under a series of applied magnetic fields is discussed. An absorption peak induced by ferromagnetic resonance appears in the range of 8-12 GHz under a certain magnetic field. Both the simulated and experimental results demonstrate that the absorption frequency of the ferrite-based MPA can be tuned by the applied magnetic field. This work provides an effective way to fabricate the magnetically tunable metamaterial perfect absorber.

  5. Matched-pair classification

    SciTech Connect

    Theiler, James P

    2009-01-01

    Following an analogous distinction in statistical hypothesis testing, we investigate variants of machine learning where the training set comes in matched pairs. We demonstrate that even conventional classifiers can exhibit improved performance when the input data has a matched-pair structure. Online algorithms, in particular, converge quicker when the data is presented in pairs. In some scenarios (such as the weak signal detection problem), matched pairs can be generated from independent samples, with the effect not only doubling the nominal size of the training set, but of providing the structure that leads to better learning. A family of 'dipole' algorithms is introduced that explicitly takes advantage of matched-pair structure in the input data and leads to further performance gains. Finally, we illustrate the application of matched-pair learning to chemical plume detection in hyperspectral imagery.

  6. Prematurely delivered rats show improved motor coordination during sensory-evoked motor responses compared to age-matched controls.

    PubMed

    Roberto, Megan E; Brumley, Michele R

    2014-05-10

    The amount of postnatal experience for perinatal rats was manipulated by delivering pups one day early (postconception day 21; PC21) by cesarean delivery and comparing their motor behavior to age-matched controls on PC22 (the typical day of birth). On PC22, pups were tested on multiple measures of motor coordination: leg extension response (LER), facial wiping, contact righting, and fore- and hindlimb stepping. The LER and facial wiping provided measures of synchronous hind- and forelimb coordination, respectively, and were sensory-evoked. Contact righting also was sensory-evoked and provided a measure of axial coordination. Stepping provided a measure of alternated forelimb and hindlimb coordination and was induced with the serotonin receptor agonist quipazine. Pups that were delivered prematurely and spent an additional day in the postnatal environment showed more bilateral limb coordination during expression of the LER and facial wiping, as well as a more mature righting strategy, compared to controls. These findings suggest that experience around the time of birth shapes motor coordination and the expression of species-typical behavior in the developing rat.

  7. Latent fingerprint matching.

    PubMed

    Jain, Anil K; Feng, Jianjiang

    2011-01-01

    Latent fingerprint identification is of critical importance to law enforcement agencies in identifying suspects: Latent fingerprints are inadvertent impressions left by fingers on surfaces of objects. While tremendous progress has been made in plain and rolled fingerprint matching, latent fingerprint matching continues to be a difficult problem. Poor quality of ridge impressions, small finger area, and large nonlinear distortion are the main difficulties in latent fingerprint matching compared to plain or rolled fingerprint matching. We propose a system for matching latent fingerprints found at crime scenes to rolled fingerprints enrolled in law enforcement databases. In addition to minutiae, we also use extended features, including singularity, ridge quality map, ridge flow map, ridge wavelength map, and skeleton. We tested our system by matching 258 latents in the NIST SD27 database against a background database of 29,257 rolled fingerprints obtained by combining the NIST SD4, SD14, and SD27 databases. The minutiae-based baseline rank-1 identification rate of 34.9 percent was improved to 74 percent when extended features were used. In order to evaluate the relative importance of each extended feature, these features were incrementally used in the order of their cost in marking by latent experts. The experimental results indicate that singularity, ridge quality map, and ridge flow map are the most effective features in improving the matching accuracy.

  8. Phenomenological study of the interplay between IR-improved DGLAP-CS theory and the precision of an NLO ME matched parton shower MC

    SciTech Connect

    Majhi, S.K.; Mukhopadhyay, A.; Ward, B.F.L.; Yost, S.A.

    2014-11-15

    We present a phenomenological study of the current status of the application of our approach of exact amplitude-based resummation in quantum field theory to precision QCD calculations, by realistic MC event generator methods, as needed for precision LHC physics. We discuss recent results as they relate to the interplay of the attendant IR-improved DGLAP-CS theory of one of us and the precision of exact NLO matrix-element matched parton shower MC’s in the Herwig6.5 environment as determined by comparison to recent LHC experimental observations on single heavy gauge boson production and decay. The level of agreement between the new theory and the data continues to be a reason for optimism. In the spirit of completeness, we discuss as well other approaches to the same theoretical predictions that we make here from the standpoint of physical precision with an eye toward the (sub-)1% QCD⊗EW total theoretical precision regime for LHC physics. - Highlights: • Using LHC data, we show that IR-improved DGLAP-CS kernels with exact NLO Shower/ME matching improves MC precision. • We discuss other possible approaches in comparison with ours. • We propose experimental tests to discriminate between competing approaches.

  9. SU-E-J-108: Template Matching Based On Multiple Templates Can Improve the Tumor Tracking Performance When There Is Large Tumor Deformation

    SciTech Connect

    Shi, X; Lin, J; Diwanji, T; Mooney, K; D'Souza, W; Mistry, N

    2014-06-01

    Purpose: Recently, template matching has been shown to be able to track tumor motion on cine-MRI images. However, artifacts such as deformation, rotation, and/or out-of-plane movement could seriously degrade the performance of this technique. In this work, we demonstrate the utility of multiple templates derived from different phases of tumor motion in reducing the negative effects of artifacts and improving the accuracy of template matching methods. Methods: Data from 2 patients with large tumors and significant tumor deformation were analyzed from a group of 12 patients from an earlier study. Cine-MRI (200 frames) imaging was performed while the patients were instructed to breathe normally. Ground truth tumor position was established on each frame manually by a radiation oncologist. Tumor positions were also automatically determined using template matching with either single or multiple (5) templates. The tracking errors, defined as the absolute differences in tumor positions determined by the manual and automated methods, when using either single or multiple templates were compared in both the AP and SI directions, respectively. Results: Using multiple templates reduced the tracking error of template matching. In the SI direction where the tumor movement and deformation were significant, the mean tracking error decreased from 1.94 mm to 0.91 mm (Patient 1) and from 6.61 mm to 2.06 mm (Patient 2). In the AP direction where the tumor movement was small, the reduction of the mean tracking error was significant in Patient 1 (from 3.36 mm to 1.04 mm), but not in Patient 2 ( from 3.86 mm to 3.80 mm). Conclusion: This study shows the effectiveness of using multiple templates in improving the performance of template matching when artifacts like large tumor deformation or out-of-plane motion exists. Accurate tumor tracking capabilities can be integrated with MRI guided radiation therapy systems. This work was supported in part by grants from NIH/NCI CA 124766 and Varian

  10. "Perfect" designer chromosome V and behavior of a ring derivative.

    PubMed

    Xie, Ze-Xiong; Li, Bing-Zhi; Mitchell, Leslie A; Wu, Yi; Qi, Xin; Jin, Zhu; Jia, Bin; Wang, Xia; Zeng, Bo-Xuan; Liu, Hui-Min; Wu, Xiao-Le; Feng, Qi; Zhang, Wen-Zheng; Liu, Wei; Ding, Ming-Zhu; Li, Xia; Zhao, Guang-Rong; Qiao, Jian-Jun; Cheng, Jing-Sheng; Zhao, Meng; Kuang, Zheng; Wang, Xuya; Martin, J Andrew; Stracquadanio, Giovanni; Yang, Kun; Bai, Xue; Zhao, Juan; Hu, Meng-Long; Lin, Qiu-Hui; Zhang, Wen-Qian; Shen, Ming-Hua; Chen, Si; Su, Wan; Wang, En-Xu; Guo, Rui; Zhai, Fang; Guo, Xue-Jiao; Du, Hao-Xing; Zhu, Jia-Qing; Song, Tian-Qing; Dai, Jun-Jun; Li, Fei-Fei; Jiang, Guo-Zhen; Han, Shi-Lei; Liu, Shi-Yang; Yu, Zhi-Chao; Yang, Xiao-Na; Chen, Ken; Hu, Cheng; Li, Da-Shuai; Jia, Nan; Liu, Yue; Wang, Lin-Ting; Wang, Su; Wei, Xiao-Tong; Fu, Mei-Qing; Qu, Lan-Meng; Xin, Si-Yu; Liu, Ting; Tian, Kai-Ren; Li, Xue-Nan; Zhang, Jin-Hua; Song, Li-Xiang; Liu, Jin-Gui; Lv, Jia-Fei; Xu, Hang; Tao, Ran; Wang, Yan; Zhang, Ting-Ting; Deng, Ye-Xuan; Wang, Yi-Ran; Li, Ting; Ye, Guang-Xin; Xu, Xiao-Ran; Xia, Zheng-Bao; Zhang, Wei; Yang, Shi-Lan; Liu, Yi-Lin; Ding, Wen-Qi; Liu, Zhen-Ning; Zhu, Jun-Qi; Liu, Ning-Zhi; Walker, Roy; Luo, Yisha; Wang, Yun; Shen, Yue; Yang, Huanming; Cai, Yizhi; Ma, Ping-Sheng; Zhang, Chun-Ting; Bader, Joel S; Boeke, Jef D; Yuan, Ying-Jin

    2017-03-10

    Perfect matching of an assembled physical sequence to a specified designed sequence is crucial to verify design principles in genome synthesis. We designed and de novo synthesized 536,024-base pair chromosome synV in the "Build-A-Genome China" course. We corrected an initial isolate of synV to perfectly match the designed sequence using integrative cotransformation and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-mediated editing in 22 steps; synV strains exhibit high fitness under a variety of culture conditions, compared with that of wild-type V strains. A ring synV derivative was constructed, which is fully functional in Saccharomyces cerevisiae under all conditions tested and exhibits lower spore viability during meiosis. Ring synV chromosome can extends Sc2.0 design principles and provides a model with which to study genomic rearrangement, ring chromosome evolution, and human ring chromosome disorders.

  11. Antithymocyte globulin improves the survival of patients with myelodysplastic syndrome undergoing HLA-matched unrelated donor and haplo-identical donor transplants

    PubMed Central

    Wang, Hong; Liu, Hong; Zhou, Jin-Yi; Zhang, Tong-Tong; Jin, Song; Zhang, Xiang; Chen, Su-Ning; Li, Wei-Yang; Xu, Yang; Miao, Miao; Wu, De-Pei

    2017-01-01

    Significant advances have been achieved in the outcomes of patients with myelodysplastic syndromes (MDS) after both HLA-matched sibling donor transplants (MSDT) and non-MSDT, the latter including HLA-matched unrelated donor (MUDT) and haplo-identical donor transplants (HIDT). In this retrospective study, we analyzed the data of 85 consecutive patients with MDS who received allogeneic HSCT between Dec 2007 and Apr 2014 in our center. These patients comprised 38 (44.7%) who received MSDT, 29 (34.1%) MUDT, and 18 (21.2%) HIDT. The median overall survival (OS) was 60.2 months, the probabilities of OS being 63%, 57%, and 48%, at the first, second, and fifth year, respectively. Median OS post-transplant (OSPT) was 57.2 months, the probabilities of OSPT being 58%, 55%, and 48% at the first, second, and fifth year, respectively. The survival of patients receiving non-MSDT was superior to that of MSDT, median OSPT being 84.0 months and 23.6 months, respectively (P = 0.042); the findings for OS were similar (P = 0.028). We also found that using ATG in conditioning regimens significantly improved survival after non-MSDT, with better OS and OSPT (P = 0.016 and P = 0.025). These data suggest that using ATG in conditioning regimens may improve the survival of MDS patients after non-MSDT. PMID:28262717

  12. The Balance Super Learner: A robust adaptation of the Super Learner to improve estimation of the average treatment effect in the treated based on propensity score matching.

    PubMed

    Pirracchio, Romain; Carone, Marco

    2016-01-01

    Consistency of the propensity score estimators rely on correct specification of the propensity score model. The propensity score is frequently estimated using a main effect logistic regression. It has recently been shown that the use of ensemble machine learning algorithms, such as the Super Learner, could improve covariate balance and reduce bias in a meaningful manner in the case of serious model misspecification for treatment assignment. However, the loss functions normally used by the Super Learner may not be appropriate for propensity score estimation since the goal in this problem is not to optimize propensity score prediction but rather to achieve the best possible balance in the covariate distribution between treatment groups. In a simulation study, we evaluated the benefit of a modification of the Super Learner by propensity score estimation geared toward achieving covariate balance between the treated and untreated after matching on the propensity score. Our simulation study included six different scenarios characterized by various degrees of deviation from the usual main term logistic model for the true propensity score and outcome as well as the presence (or not) of instrumental variables. Our results suggest that the use of this adapted Super Learner to estimate the propensity score can further improve the robustness of propensity score matching estimators.

  13. Learning graph matching.

    PubMed

    Caetano, Tibério S; McAuley, Julian J; Cheng, Li; Le, Quoc V; Smola, Alex J

    2009-06-01

    As a fundamental problem in pattern recognition, graph matching has applications in a variety of fields, from computer vision to computational biology. In graph matching, patterns are modeled as graphs and pattern recognition amounts to finding a correspondence between the nodes of different graphs. Many formulations of this problem can be cast in general as a quadratic assignment problem, where a linear term in the objective function encodes node compatibility and a quadratic term encodes edge compatibility. The main research focus in this theme is about designing efficient algorithms for approximately solving the quadratic assignment problem, since it is NP-hard. In this paper we turn our attention to a different question: how to estimate compatibility functions such that the solution of the resulting graph matching problem best matches the expected solution that a human would manually provide. We present a method for learning graph matching: the training examples are pairs of graphs and the 'labels' are matches between them. Our experimental results reveal that learning can substantially improve the performance of standard graph matching algorithms. In particular, we find that simple linear assignment with such a learning scheme outperforms Graduated Assignment with bistochastic normalisation, a state-of-the-art quadratic assignment relaxation algorithm.

  14. Effective perfect fluids in cosmology

    SciTech Connect

    Ballesteros, Guillermo; Bellazzini, Brando E-mail: brando.bellazzini@pd.infn.it

    2013-04-01

    We describe the cosmological dynamics of perfect fluids within the framework of effective field theories. The effective action is a derivative expansion whose terms are selected by the symmetry requirements on the relevant long-distance degrees of freedom, which are identified with comoving coordinates. The perfect fluid is defined by requiring invariance of the action under internal volume-preserving diffeomorphisms and general covariance. At lowest order in derivatives, the dynamics is encoded in a single function of the entropy density that characterizes the properties of the fluid, such as the equation of state and the speed of sound. This framework allows a neat simultaneous description of fluid and metric perturbations. Longitudinal fluid perturbations are closely related to the adiabatic modes, while the transverse modes mix with vector metric perturbations as a consequence of vorticity conservation. This formalism features a large flexibility which can be of practical use for higher order perturbation theory and cosmological parameter estimation.

  15. Flu Vaccine a Pretty Good Match for Viruses This Year: CDC

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_163624.html Flu Vaccine a Pretty Good Match for Viruses This Year: ... News) -- It's not perfect, but this year's flu vaccine is a fairly good match for the circulating ...

  16. Color matching in facial prosthetics: A systematic review.

    PubMed

    Ranabhatt, Rani; Singh, Kamleshwar; Siddharth, Ramashanker; Tripathi, Shuchi; Arya, Deeksha

    2017-01-01

    Color matching to the surrounding skin is extremely important in patients wearing maxillofacial prostheses. It is of utmost importance to know the different techniques of color matching and coloring in maxillofacial prostheses. The purpose of this study is to review the literature data with regard to color matching in maxillofacial prosthetics. An electronic search of peer review restricted to English language dental literature was conducted to identify the relevant scientific article on color matching and coloring in maxillofacial prostheses. The publication year was up to December 2015 so that the search could include all the articles provided in that particular database. Two independent observers independently read the abstracts and later preselected full-text articles. A full-text review was carried out only for 15 articles. Out of the 15 articles, 7 were related to coloring using tinting, spraying, milling, and use of commercial cosmetics. Three studies were related to shade matching in maxillofacial prostheses. Two studies conducted the measurement of color in maxillofacial prostheses. Only one study had explained color and its relevance in maxillofacial prosthetics. Only one study was done for reproducing silicone shade guide matching Indian skin color. In addition, a single pilot study was done to measure facial skin and lip color in a human population sample stratified by race, gender, and age. Currently, there is no evidence discussing the best technique available for perfectly matching the color for the fabrication of maxillofacial prostheses. However, the latest instruments such as spectrophotometer and colorimeters are believed to have improved efficiency in matching the color.

  17. Screen-detected colorectal cancers are associated with an improved outcome compared with stage-matched interval cancers

    PubMed Central

    Gill, M D; Bramble, M G; Hull, M A; Mills, S J; Morris, E; Bradburn, D M; Bury, Y; Parker, C E; Lee, T J W; Rees, C J

    2014-01-01

    Background: Colorectal cancers (CRCs) detected through the NHS Bowel Cancer Screening Programme (BCSP) have been shown to have a more favourable outcome compared to non-screen-detected cancers. The aim was to identify whether this was solely due to the earlier stage shift of these cancers, or whether other factors were involved. Methods: A combination of a regional CRC registry (Northern Colorectal Cancer Audit Group) and the BCSP database were used to identify screen-detected and interval cancers (diagnosed after a negative faecal occult blood test, before the next screening round), diagnosed between April 2007 and March 2010, within the North East of England. For each Dukes' stage, patient demographics, tumour characteristics, and survival rates were compared between these two groups. Results: Overall, 322 screen-detected cancers were compared against 192 interval cancers. Screen-detected Dukes' C and D CRCs had a superior survival rate compared with interval cancers (P=0.014 and P=0.04, respectively). Cox proportional hazards regression showed that Dukes' stage, tumour location, and diagnostic group (HR 0.45, 95% CI 0.29–0.69, P<0.001 for screen-detected CRCs) were all found to have a significant impact on the survival of patients. Conclusions: The improved survival of screen-detected over interval cancers for stages C and D suggest that there may be a biological difference in the cancers in each group. Although lead-time bias may have a role, this may be related to a tumour's propensity to bleed and therefore may reflect detection through current screening tests. PMID:25247322

  18. Synergistic effect of KIR ligands missing and cytomegalovirus reactivation in improving outcomes of haematopoietic stem cell transplantation from HLA-matched sibling donor for treatment of myeloid malignancies.

    PubMed

    Cardozo, Daniela Maira; Marangon, Amanda Vansan; da Silva, Rodrigo Fernandes; Aranha, Francisco José Penteado; Visentainer, Jeane Eliete Laguila; Bonon, Sandra Helena Alves; Costa, Sandra Cecília Botelho; Miranda, Eliana Cristina Martins; de Souza, Carmino Antonio; Guimarães, Fernando

    2016-10-01

    The goal of this study was to evaluate the influence of KIR-HLA genotypes on the outcome of patients undergoing treatment for haematological malignancies by non-T-depleted lymphocyte haematopoietic stem cell transplantation (HSCT) from HLA-matched sibling donors. The prospective study was conducted at the Center of Hematology, University of Campinas, and 50 patients and their donors were followed up from 2008 to 2014. KIR and HLA class I genes were genotyped and patients grouped based on the presence of KIR ligands combined with KIR genotype of their respective donors. Patients with all KIR ligands present (n=13) had a significantly higher (p=0.04) incidence of acute graft-versus-host-disease (GVHD) than patients with one or more KIR ligands missing (n=37). The overall survival following transplantation of patients with myeloid malignancies (n=27) was significantly higher (p=0.035) in the group with one or more KIR ligands missing (n=18) than in the group with all ligands present (n=9). Presence of KIR2DS2 was associated with a worsening of HSCT outcome while reactivation of cytomegalovirus (CMV) infection improved the outcome of patients with one or more KIR ligands missing. Our results indicate that KIR-HLA interactions affect the outcome of the HLA-matched transplantation, particularly in patients with myeloid malignancies.

  19. Invisible plasmonic meta-materials through impedance matching to vacuum.

    PubMed

    Lee, J W; Seo, M A; Sohn, J Y; Ahn, Y H; Kim, D S; Jeoung, S C; Lienau, Ch; Park, Q-Han

    2005-12-26

    We report on perfect transmission in two-dimensional plasmonic matamaterials in the terahertz frequency range, in which zeroth order transmittance becomes essentially unity near specific resonance frequencies. Perfect transmission may occur when the plasmonic metamaterials are perfectly impedance matched to vacuum, which is equivalent to designing an effective dielectric constant around epsilonr = -2. When the effective dielectric constant of the metamaterial is tuned towards epsilonr and the hole coverage is larger than 0.2, strong evanescent field builds up in the near field, making perfect transmission possible.

  20. Feature-accelerated block matching

    NASA Astrophysics Data System (ADS)

    Tao, Bo; Orchard, Michael T.

    1998-01-01

    We study the relationship between local features and block matching in this paper. We show that the use of many features can greatly improve the block matching results by introducing several fast block matching algorithms. The first algorithm is pixel decimation-based. We show that pixels with larger gradient magnitude have larger motion compensation error. Therefore for pixel decimation-based fast block matching, it benefits to subsample the block by selecting pixels with the largest gradient magnitude. Such a gradient-assisted adaptive pixel selection strategy greatly outperforms two other subsampling procedures proposed in previous literature. Fast block matching can achieve the optimal performance obtained using full search. We present a family of such fast block matching algorithm using various local features, such as block mean and variance. Our algorithm reduces more than 80 percent computation, while achieving the same performance as the full search. This present a brand new approach toward fast block matching algorithm design.

  1. Matching isotopic distributions from metabolically labeled samples

    PubMed Central

    McIlwain, Sean; Page, David; Huttlin, Edward L.; Sussman, Michael R.

    2008-01-01

    Motivation: In recent years stable isotopic labeling has become a standard approach for quantitative proteomic analyses. Among the many available isotopic labeling strategies, metabolic labeling is attractive for the excellent internal control it provides. However, analysis of data from metabolic labeling experiments can be complicated because the spacing between labeled and unlabeled forms of each peptide depends on its sequence, and is thus variable from analyte to analyte. As a result, one generally needs to know the sequence of a peptide to identify its matching isotopic distributions in an automated fashion. In some experimental situations it would be necessary or desirable to match pairs of labeled and unlabeled peaks from peptides of unknown sequence. This article addresses this largely overlooked problem in the analysis of quantitative mass spectrometry data by presenting an algorithm that not only identifies isotopic distributions within a mass spectrum, but also annotates matches between natural abundance light isotopic distributions and their metabolically labeled counterparts. This algorithm is designed in two stages: first we annotate the isotopic peaks using a modified version of the IDM algorithm described last year; then we use a probabilistic classifier that is supplemented by dynamic programming to find the metabolically labeled matched isotopic pairs. Such a method is needed for high-throughput quantitative proteomic metabolomic experiments measured via mass spectrometry. Results: The primary result of this article is that the dynamic programming approach performs well given perfect isotopic distribution annotations. Our algorithm achieves a true positive rate of 99% and a false positive rate of 1% using perfect isotopic distribution annotations. When the isotopic distributions are annotated given ‘expert’ selected peaks, the same algorithm gets a true positive rate of 77% and a false positive rate of 1%. Finally, when annotating using

  2. Broadband quasi perfect absorption using chirped multi-layer porous materials

    NASA Astrophysics Data System (ADS)

    Jiménez, N.; Romero-García, V.; Cebrecos, A.; Picó, R.; Sánchez-Morcillo, V. J.; Garcia-Raffi, L. M.

    2016-12-01

    This work theoretically analyzes the sound absorption properties of a chirped multi-layer porous material including transmission, in particular showing the broadband unidirectional absorption properties of the system. Using the combination of the impedance matching condition and the balance between the leakage and the intrinsic losses, the system is designed to have broadband unidirectional and quasi perfect absorption. The transfer and scattering matrix formalism, together with numerical simulations based on the finite element method are used to demonstrate the results showing excellent agreement between them. The proposed system allows to construct broadband sound absorbers with improved absorption in the low frequency regime using less amount of material than the complete bulk porous layer.

  3. Mechanism of resonant perfect optical absorber, design rules, and applications

    NASA Astrophysics Data System (ADS)

    Guan, Zhiqiang; Wang, Wenqiang; Xu, Hongxing

    2016-11-01

    The mechanism of resonant perfect optical absorber (POA) is revealed by coupled mode method. The POA structures here is an air/grating/film/air four region asymmetric structures. Different with common POA structures that require metal film at the bottom to block the transmission of light, the film in our structures serves as a total internal reflection layer which blocks the transmission of light. To demonstrate that, mode dispersion analyses are provided for each mode by the phase plots of the scattering coefficients on each interface. The sufficient and necessary conditions of perfect optical absorption are derived from the phase matching conditions. Three analytical formulae are given for prompt and accurate design rules when the incident wavelength is slightly larger than the periodicity. Several fabrication schemes are discussed. The features of ultrathin structures, widely tunable POA wavelength, and high Q factor make our structures promising for applications in coherent thermal emission, filtering, sensing and modulation.

  4. Perfect crystals grown from imperfect interfaces.

    PubMed

    Falub, Claudiu V; Meduňa, Mojmír; Chrastina, Daniel; Isa, Fabio; Marzegalli, Anna; Kreiliger, Thomas; Taboada, Alfonso G; Isella, Giovanni; Miglio, Leo; Dommann, Alex; von Känel, Hans

    2013-01-01

    The fabrication of advanced devices increasingly requires materials with different properties to be combined in the form of monolithic heterostructures. In practice this means growing epitaxial semiconductor layers on substrates often greatly differing in lattice parameters and thermal expansion coefficients. With increasing layer thickness the relaxation of misfit and thermal strains may cause dislocations, substrate bowing and even layer cracking. Minimizing these drawbacks is therefore essential for heterostructures based on thick layers to be of any use for device fabrication. Here we prove by scanning X-ray nanodiffraction that mismatched Ge crystals epitaxially grown on deeply patterned Si substrates evolve into perfect structures away from the heavily dislocated interface. We show that relaxing thermal and misfit strains result just in lattice bending and tiny crystal tilts. We may thus expect a new concept in which continuous layers are replaced by quasi-continuous crystal arrays to lead to dramatically improved physical properties.

  5. Perfect crystals grown from imperfect interfaces

    PubMed Central

    Falub, Claudiu V.; Meduňa, Mojmír; Chrastina, Daniel; Isa, Fabio; Marzegalli, Anna; Kreiliger, Thomas; Taboada, Alfonso G.; Isella, Giovanni; Miglio, Leo; Dommann, Alex; von Känel, Hans

    2013-01-01

    The fabrication of advanced devices increasingly requires materials with different properties to be combined in the form of monolithic heterostructures. In practice this means growing epitaxial semiconductor layers on substrates often greatly differing in lattice parameters and thermal expansion coefficients. With increasing layer thickness the relaxation of misfit and thermal strains may cause dislocations, substrate bowing and even layer cracking. Minimizing these drawbacks is therefore essential for heterostructures based on thick layers to be of any use for device fabrication. Here we prove by scanning X-ray nanodiffraction that mismatched Ge crystals epitaxially grown on deeply patterned Si substrates evolve into perfect structures away from the heavily dislocated interface. We show that relaxing thermal and misfit strains result just in lattice bending and tiny crystal tilts. We may thus expect a new concept in which continuous layers are replaced by quasi-continuous crystal arrays to lead to dramatically improved physical properties. PMID:23880632

  6. Relaxation matching algorithm for moving photogrammetry

    NASA Astrophysics Data System (ADS)

    Guo, Lei; Liu, Ke; Miao, Yinxiao; Zhu, Jigui

    2015-02-01

    Moving photogrammetry is an application of close range photogrammetry in industrial measurement to realize threedimensional coordinate measurement within large-scale volume. This paper describes an approach of relaxation matching algorithm applicable to moving photogrammetry according to the characteristics of accurate matching result of different measuring images. This method uses neighborhood matching support to improve the matching rate after coarse matching based on epipolar geometry constraint and precise matching using three images. It reflects the overall matching effect of all points, that means when a point is matched correctly, the matching results of those points round it must be correct. So for one point considered, the matching results of points round it are calculated to judge whether its result is correct. Analysis indicates that relaxation matching can eliminate the mismatching effectively and acquire 100% rate of correct matching. It will play a very important role in moving photogrammetry to ensure the following implement of ray bundle adjustment.

  7. The Perfect Storm and the Privatization of Public Higher Education

    ERIC Educational Resources Information Center

    Ehrenberg, Ronald G.

    2006-01-01

    During the last quarter of a century, public higher education institutions have found themselves buffeted by a perfect storm. This storm has led to discussions about the privatization of those institutions, which has implications for their ability to improve, or at least maintain, their quality and their accessibility to students from all…

  8. Measurement of 3-D Vibrational Motion by Dynamic Photogrammetry Using Least-Square Image Matching for Sub-Pixel Targeting to Improve Accuracy.

    PubMed

    Lee, Hyoseong; Rhee, Huinam; Oh, Jae Hong; Park, Jin Ho

    2016-03-11

    This paper deals with an improved methodology to measure three-dimensional dynamic displacements of a structure by digital close-range photogrammetry. A series of stereo images of a vibrating structure installed with targets are taken at specified intervals by using two daily-use cameras. A new methodology is proposed to accurately trace the spatial displacement of each target in three-dimensional space. This method combines the correlation and the least-square image matching so that the sub-pixel targeting can be obtained to increase the measurement accuracy. Collinearity and space resection theory are used to determine the interior and exterior orientation parameters. To verify the proposed method, experiments have been performed to measure displacements of a cantilevered beam excited by an electrodynamic shaker, which is vibrating in a complex configuration with mixed bending and torsional motions simultaneously with multiple frequencies. The results by the present method showed good agreement with the measurement by two laser displacement sensors. The proposed methodology only requires inexpensive daily-use cameras, and can remotely detect the dynamic displacement of a structure vibrating in a complex three-dimensional defection shape up to sub-pixel accuracy. It has abundant potential applications to various fields, e.g., remote vibration monitoring of an inaccessible or dangerous facility.

  9. Measurement of 3-D Vibrational Motion by Dynamic Photogrammetry Using Least-Square Image Matching for Sub-Pixel Targeting to Improve Accuracy

    PubMed Central

    Lee, Hyoseong; Rhee, Huinam; Oh, Jae Hong; Park, Jin Ho

    2016-01-01

    This paper deals with an improved methodology to measure three-dimensional dynamic displacements of a structure by digital close-range photogrammetry. A series of stereo images of a vibrating structure installed with targets are taken at specified intervals by using two daily-use cameras. A new methodology is proposed to accurately trace the spatial displacement of each target in three-dimensional space. This method combines the correlation and the least-square image matching so that the sub-pixel targeting can be obtained to increase the measurement accuracy. Collinearity and space resection theory are used to determine the interior and exterior orientation parameters. To verify the proposed method, experiments have been performed to measure displacements of a cantilevered beam excited by an electrodynamic shaker, which is vibrating in a complex configuration with mixed bending and torsional motions simultaneously with multiple frequencies. The results by the present method showed good agreement with the measurement by two laser displacement sensors. The proposed methodology only requires inexpensive daily-use cameras, and can remotely detect the dynamic displacement of a structure vibrating in a complex three-dimensional defection shape up to sub-pixel accuracy. It has abundant potential applications to various fields, e.g., remote vibration monitoring of an inaccessible or dangerous facility. PMID:26978366

  10. Using social-emotional and character development to improve academic outcomes: a matched-pair, cluster-randomized controlled trial in low-income, urban schools

    PubMed Central

    Lewis, Kendra M.; DuBois, David L.; Acock, Alan; Vuchinich, Samuel; Silverthorn, Naida; Snyder, Frank J.; Day, Joseph; Ji, Peter; Flay, Brian R.

    2013-01-01

    BACKGROUND School-based social-emotional and character development (SECD) programs can influence not only SECD, but also academic-related outcomes. This study evaluated the impact of one SECD program, Positive Action (PA), on educational outcomes among low-income, urban youth. METHODS The longitudinal study used a matched-pair, cluster-randomized controlled design. Student-reported disaffection with learning and academic grades, and teacher ratings of academic ability and motivation were assessed for a cohort followed from grades 3 to 8. Aggregate school records were used to assess standardized test performance (for entire school, cohort, and demographic subgroups) and absenteeism (entire school). Multilevel growth-curve analyses tested program effects. RESULTS PA significantly improved growth in academic motivation and mitigated disaffection with learning. There was a positive impact of PA on absenteeism and marginally significant impact on math performance of all students. There were favorable program effects on reading for African American boys and cohort students transitioning between grades 7 and 8, and on math for girls and low-income students. CONCLUSIONS A school-based SECD program was found to influence academic outcomes among students living in low-income, urban communities. Future research should examine mechanisms by which changes in SECD influence changes in academic outcomes. PMID:24138347

  11. Is matching innate?

    PubMed

    Gallistel, C R; King, Adam Philip; Gottlieb, Daniel; Balci, Fuat; Papachristos, Efstathios B; Szalecki, Matthew; Carbone, Kimberly S

    2007-03-01

    Experimentally naive mice matched the proportions of their temporal investments (visit durations) in two feeding hoppers to the proportions of the food income (pellets per unit session time) derived from them in three experiments that varied the coupling between the behavioral investment and food income, from no coupling to strict coupling. Matching was observed from the outset; it did not improve with training. When the numbers of pellets received were proportional to time invested, investment was unstable, swinging abruptly from sustained, almost complete investment in one hopper, to sustained, almost complete investment in the other-in the absence of appropriate local fluctuations in returns (pellets obtained per time invested). The abruptness of the swings strongly constrains possible models. We suggest that matching reflects an innate (unconditioned) program that matches the ratio of expected visit durations to the ratio between the current estimates of expected incomes. A model that processes the income stream looking for changes in the income and generates discontinuous income estimates when a change is detected is shown to account for salient features of the data.

  12. Factorized Graph Matching.

    PubMed

    Zhou, Feng; de la Torre, Fernando

    2015-11-19

    Graph matching (GM) is a fundamental problem in computer science, and it plays a central role to solve correspondence problems in computer vision. GM problems that incorporate pairwise constraints can be formulated as a quadratic assignment problem (QAP). Although widely used, solving the correspondence problem through GM has two main limitations: (1) the QAP is NP-hard and difficult to approximate; (2) GM algorithms do not incorporate geometric constraints between nodes that are natural in computer vision problems. To address aforementioned problems, this paper proposes factorized graph matching (FGM). FGM factorizes the large pairwise affinity matrix into smaller matrices that encode the local structure of each graph and the pairwise affinity between edges. Four are the benefits that follow from this factorization: (1) There is no need to compute the costly (in space and time) pairwise affinity matrix; (2) The factorization allows the use of a path-following optimization algorithm, that leads to improved optimization strategies and matching performance; (3) Given the factorization, it becomes straight-forward to incorporate geometric transformations (rigid and non-rigid) to the GM problem. (4) Using a matrix formulation for the GM problem and the factorization, it is easy to reveal commonalities and differences between different GM methods. The factorization also provides a clean connection with other matching algorithms such as iterative closest point; Experimental results on synthetic and real databases illustrate how FGM outperforms state-of-the-art algorithms for GM. The code is available at http://humansensing.cs.cmu.edu/fgm.

  13. Matching Supernovae to Galaxies

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-12-01

    developed a new automated algorithm for matching supernovae to their host galaxies. Their work builds on currently existing algorithms and makes use of information about the nearby galaxies, accounts for the uncertainty of the match, and even includes a machine learning component to improve the matching accuracy.Gupta and collaborators test their matching algorithm on catalogs of galaxies and simulated supernova events to quantify how well the algorithm is able to accurately recover the true hosts.Successful MatchingThe matching algorithms accuracy (purity) as a function of the true supernova-host separation, the supernova redshift, the true hosts brightness, and the true hosts size. [Gupta et al. 2016]The authors find that when the basic algorithm is run on catalog data, it matches supernovae to their hosts with 91% accuracy. Including the machine learning component, which is run after the initial matching algorithm, improves the accuracy of the matching to 97%.The encouraging results of this work which was intended as a proof of concept suggest that methods similar to this could prove very practical for tackling future survey data. And the method explored here has use beyond matching just supernovae to their host galaxies: it could also be applied to other extragalactic transients, such as gamma-ray bursts, tidal disruption events, or electromagnetic counterparts to gravitational-wave detections.CitationRavi R. Gupta et al 2016 AJ 152 154. doi:10.3847/0004-6256/152/6/154

  14. Computation of Thermally Perfect Compressible Flow Properties

    NASA Technical Reports Server (NTRS)

    Witte, David W.; Tatum, Kenneth E.; Williams, S. Blake

    1996-01-01

    A set of compressible flow relations for a thermally perfect, calorically imperfect gas are derived for a value of c(sub p) (specific heat at constant pressure) expressed as a polynomial function of temperature and developed into a computer program, referred to as the Thermally Perfect Gas (TPG) code. The code is available free from the NASA Langley Software Server at URL http://www.larc.nasa.gov/LSS. The code produces tables of compressible flow properties similar to those found in NACA Report 1135. Unlike the NACA Report 1135 tables which are valid only in the calorically perfect temperature regime the TPG code results are also valid in the thermally perfect, calorically imperfect temperature regime, giving the TPG code a considerably larger range of temperature application. Accuracy of the TPG code in the calorically perfect and in the thermally perfect, calorically imperfect temperature regimes are verified by comparisons with the methods of NACA Report 1135. The advantages of the TPG code compared to the thermally perfect, calorically imperfect method of NACA Report 1135 are its applicability to any type of gas (monatomic, diatomic, triatomic, or polyatomic) or any specified mixture of gases, ease-of-use, and tabulated results.

  15. Conditions for creating perfectly secure systems

    NASA Astrophysics Data System (ADS)

    Styugin, M.

    2016-11-01

    The present paper reviews a method for establishing secure information systems by complicating the possibility to research them for potential adversaries. A formalized model of a researcher and a definition of a research secure system are presented. A theorem for conditions required for creating a system perfectly secured from research. The Shannon's theorem of absolute security of perfect secrecy ciphers in cryptography is an instance of the theorem presented in the paper.

  16. Using Social-Emotional and Character Development to Improve Academic Outcomes: A Matched-Pair, Cluster-Randomized Controlled Trial in Low-Income, Urban Schools

    ERIC Educational Resources Information Center

    Bavarian, Niloofar; Lewis, Kendra M.; DuBois, David L.; Acock, Alan; Vuchinich, Samuel; Silverthorn, Naida; Snyder, Frank J.; Day, Joseph; Ji, Peter; Flay, Brian R.

    2013-01-01

    Background: School-based social-emotional and character development (SECD) programs can influence not only SECD but also academic-related outcomes. This study evaluated the impact of one SECD program, Positive Action (PA), on educational outcomes among low-income, urban youth. Methods: The longitudinal study used a matched-pair, cluster-randomized…

  17. A Modified Protocol with Improved Detection Rate for Mis-Matched Donor HLA from Low Quantities of DNA in Urine Samples from Kidney Graft Recipients

    PubMed Central

    Kwok, Janette; Choi, Leo C. W.; Ho, Jenny C. Y.; Chan, Gavin S. W.; Mok, Maggie M. Y.; Lam, Man-Fei; Chak, Wai-Leung; Cheuk, Au; Chau, Ka-Foon; Tong, Matthew; Chan, Kwok-Wah; Chan, Tak-Mao

    2016-01-01

    Background Urine from kidney transplant recipient has proven to be a viable source for donor DNA. However, an optimized protocol would be required to determine mis-matched donor HLA specificities in view of the scarcity of DNA obtained in some cases. Methods In this study, fresh early morning urine specimens were obtained from 155 kidney transplant recipients with known donor HLA phenotype. DNA was extracted and typing of HLA-A, B and DRB1 loci by polymerase chain reaction-specific sequence primers was performed using tailor-made condition according to the concentration of extracted DNA. Results HLA typing of DNA extracted from urine revealed both recipient and donor HLA phenotypes, allowing the deduction of the unknown donor HLA and hence the degree of HLA mis-match. By adopting the modified procedures, mis-matched donor HLA phenotypes were successfully deduced in all of 35 tested urine samples at DNA quantities spanning the range of 620–24,000 ng. Conclusions This urine-based method offers a promising and reliable non-invasive means for the identification of mis-matched donor HLA antigens in kidney transplant recipients with unknown donor HLA phenotype or otherwise inadequate donor information. PMID:27861530

  18. Hybrid Schema Matching for Deep Web

    NASA Astrophysics Data System (ADS)

    Chen, Kerui; Zuo, Wanli; He, Fengling; Chen, Yongheng

    Schema matching is the process of identifying semantic mappings, or correspondences, between two or more schemas. Schema matching is a first step and critical part of data integration. For schema matching of deep web, most researches only interested in query interface, while rarely pay attention to abundant schema information contained in query result pages. This paper proposed a mixed schema matching technique, which combines attributes that appeared in query structures and query results of different data sources, and mines the matched schemas inside. Experimental results prove the effectiveness of this method for improving the accuracy of schema matching.

  19. Random perfect lattices and the sphere packing problem

    NASA Astrophysics Data System (ADS)

    Andreanov, A.; Scardicchio, A.

    2012-10-01

    Motivated by the search for best lattice sphere packings in Euclidean spaces of large dimensions we study randomly generated perfect lattices in moderately large dimensions (up to d=19 included). Perfect lattices are relevant in the solution of the problem of lattice sphere packing, because the best lattice packing is a perfect lattice and because they can be generated easily. Their number, however, grows superexponentially with the dimension, so to get an idea of their properties we propose to study a randomized version of the generating algorithm and to define a random ensemble with an effective temperature in a way reminiscent of a Monte Carlo simulation. We therefore study the distribution of packing fractions and kissing numbers of these ensembles and show how as the temperature is decreased the best known packers are easily recovered. We find that, even at infinite temperature, the typical perfect lattices are considerably denser than known families (like Ad and Dd), and we propose two hypotheses between which we cannot distinguish in this paper: one in which they improve the Minkowsky bound φ˜2-(0.84±0.06)d, and a competitor in which their packing fraction decreases superexponentially, namely, φ˜d-ad but with a very small coefficient a=0.06±0.04. We also find properties of the random walk which are suggestive of a glassy system already for moderately small dimensions. We also analyze local structure of network of perfect lattices conjecturing that this is a scale-free network in all dimensions with constant scaling exponent 2.6±0.1.

  20. Pursuing the perfect patient experience.

    PubMed

    Kaplan, Gary S

    2013-01-01

    Adapting the principles and tools of the Toyota Production System to healthcare in the form of the Virginia Mason Production System has enabled Virginia Mason Medical Center to transform itself as an organization. Virginia Mason has worked persistently for more than a decade to apply Toyota methods to eliminate waste, improve safety and quality, and provide the community it serves with the highest-quality healthcare at the lowest cost. We have made great progress in this pursuit.

  1. Persistent Perfect Entanglement in Atomic Systems

    NASA Astrophysics Data System (ADS)

    Ali Can, Muhammet

    2004-03-01

    It has been shown recently [1] that a pure entangled state of two-level atoms can be obtained in an optical resonator through the exchange by cavity photons. Unfortunately, the lifetime of such an entangled state, caused by the radiative decay time for the dipole transitions is very short. The situation can be improved through the use of three-level atoms with lambda-type transition [2]. In this case, the cavity field pumps transition between the lowest (ground) and highest (excited) states. Then, the decay of the excited state can populate the intermediate state. This is just the Raman-type process with emission of Stokes photon in atomic system. Because of the selection rules by the parity conservation, the dipole decay from the intermediate state to the ground state is forbidden. If the Stokes photons created by the transitions from the excited state to the ground state are discarded (through the use of cavity leakage of absorption), the final state of atomic system is stabile or at least durable. In the case of 2n three-level atoms, this can lead to the N-qubit perfect entangled state, where N=2j+1 and j is an odd ``spin'' corresponding to the SU(2) algebra in the Hilbert space H=(C2)^ otimes N In fact, these are the SU(2) phase states of odd ``spin'' have been discussed in [3] in the context of two-level atoms. The possibility to create and observe these states with present experimental technique is discussed. [1] A. Beige, S. Bose, D. Braun, S.F. Huelga, P.L. Knight, M.B. Plenio, and V. Verdal. J. Mod. Optics 47, 2583 (2000). [2] M.A. Can, A.A. Klyachko, and A.S. Shumovsky. Appl. Phys. Lett. 81, 5072 (2002). [3] M.A. Can, A.A. Klyachko, and A.S. Shumovsky. Phys. Rev. A 66, 022111 (2002).

  2. Overlapped optics induced perfect coherent effects

    NASA Astrophysics Data System (ADS)

    Li, Jian Jie; Zang, Xiao Fei; Mao, Jun Fa; Tang, Min; Zhu, Yi Ming; Zhuang, Song Lin

    2013-12-01

    For traditional coherent effects, two separated identical point sources can be interfered with each other only when the optical path difference is integer number of wavelengths, leading to alternate dark and bright fringes for different optical path difference. For hundreds of years, such a perfect coherent condition seems insurmountable. However, in this paper, based on transformation optics, two separated in-phase identical point sources can induce perfect interference with each other without satisfying the traditional coherent condition. This shifting illusion media is realized by inductor-capacitor transmission line network. Theoretical analysis, numerical simulations and experimental results are performed to confirm such a kind of perfect coherent effect and it is found that the total radiation power of multiple elements system can be greatly enhanced. Our investigation may be applicable to National Ignition Facility (NIF), Inertial Confined Fusion (ICF) of China, LED lighting technology, terahertz communication, and so on.

  3. Patient HSP70-hom TG haplotype is associated with decreased transplant-related mortality and improved survival after sibling HLA-matched hematopoietic stem cell transplantation.

    PubMed

    Kim, Inho; Kim, Jin Hee; Rhee, Ji Young; Kim, Jin Won; Cho, Hyeon Jin; Cho, Eun-Young; Lee, Jong-Eun; Hong, Yun-Chul; Park, Sung Sup; Yoon, Sung-Soo; Park, Myoung Hee; Park, Seonyang; Kim, Byoung Kook

    2010-01-01

    Heat shock protein 70-hom (HSP70-hom) plays an important role in protein folding and immune responses. Therefore, HSP70-hom gene polymorphisms may act as important factors in predicting the prognosis of patients receiving allogeneic hematopoietic stem cell transplantation (HSCT). To evaluate the role of HSP70-hom gene polymorphisms in the prognosis of patients receiving sibling human leukocyte antigen (HLA)-matched allogeneic HSCT, the HSP70-hom polymorphisms, T2437C and G2763A, were genotyped in 147 patients receiving sibling HLA-matched allogeneic HSCT. Individual diplotypes were estimated from genotype data of the two HSP70-hom polymorphisms using the expectation maximization algorithm. Patients with the 2763GG or GA genotype showed longer overall survival compared with those with the 2763AA genotype, and patients with a TG haplotype (TG/TA, TG/TG or TG/CG) also showed longer overall survival compared with those with a non-TG haplotype (TA/TA or TA/CG) (both G2763A genotype and diplotype, p<0.01). Moreover, the 2437TT genotype was found to be protective for treatment-related death compared with the 2437TC genotype, and a TG haplotype was found to be very protective for treatment-related death compared with a non-TG haplotype (T2437C genotype, p=0.04; and diplotype, p=0.02). Therefore, our results suggest that HSP70-hom polymorphisms play an important role in the prognosis of patients receiving sibling HLA-matched allogeneic HSCT.

  4. Skyline based terrain matching

    NASA Technical Reports Server (NTRS)

    Page, Lance A.

    1990-01-01

    Skyline-based terrain matching, a new method for locating the vantage point of stereo camera or laser range-finding measurements on a global map previously prepared by satellite or aerial mapping is described. The orientation of the vantage is assumed known, but its translational parameters are determined by the algorithm. Skylines, or occluding contours, can be extracted from the sensory measurements taken by an autonomous vehicle. They can also be modeled from the global map, given a vantage estimate from which to start. The two sets of skylines, represented in cylindrical coordinates about either the true or the estimated vantage, are employed as 'features' or reference objects common to both sources of information. The terrain matching problem is formulated in terms of finding a translation between the respective representations of the skylines, by approximating the two sets of skylines as identical features (curves) on the actual terrain. The search for this translation is based on selecting the longest of the minimum-distance vectors between corresponding curves from the two sets of skylines. In successive iterations of the algorithm, the approximation that the two sets of curves are identical becomes more accurate, and the vantage estimate continues to improve. The algorithm was implemented and evaluated on a simulated terrain. Illustrations and examples are included.

  5. Selective coherent perfect absorption in metamaterials

    SciTech Connect

    Nie, Guangyu; Shi, Quanchao; Zhu, Zheng; Shi, Jinhui

    2014-11-17

    We show multi-band coherent perfect absorption (CPA) in simple bilayered asymmetrically split ring metamaterials. The selectivity of absorption can be accomplished by separately excited electric and magnetic modes in a standing wave formed by two coherent counterpropagating beams. In particular, each CPA can be completely switched on/off by the phase of a second coherent wave. We propose a practical scheme for realizing multi-band coherent perfect absorption of 100% that is allowed to work from microwave to optical frequency.

  6. Near-perfect diffraction grating rhomb

    DOEpatents

    Wantuck, Paul J.

    1990-01-01

    A near-perfect grating rhomb enables an output beam to be diffracted to an angle offset from the input beam. The correcting grating is tipped relative to the dispersing grating to provide the offset angle. The correcting grating is further provided with a groove spacing which differs from the dispersing grating groove space by an amount effective to substantially remove angular dispersion in the output beam. A near-perfect grating rhomb has the capability for selective placement in a FEL to suppress sideband instabilities arising from the FEL.

  7. Electromagnetic Detection of a Perfect Invisibility Cloak

    SciTech Connect

    Zhang Baile; Wu, Bae-Ian

    2009-12-11

    A perfect invisibility cloak is commonly believed to be undetectable from electromagnetic (EM) detection because it is equivalent to a curved but empty EM space created from coordinate transformation. Based on the intrinsic asymmetry of coordinate transformation applied to motions of photons and charges, we propose a method to detect this curved EM space by shooting a fast-moving charged particle through it. A broadband radiation generated in this process makes a cloak visible. Our method is the only known EM mechanism so far to detect an ideal perfect cloak (curved EM space) within its working band.

  8. [THE RIGHT TO A CHROMOSOMICALLY PERFECT CHILD].

    PubMed

    Vago, Philippe

    2015-07-01

    After defining the terms "perfect," "chromosomically" and "right" we discuss on the scope and terms of the right to a chromosomically perfect child. This right is it addressed to a target population or to the general population? What are the exams available and the means of diagnosis or screening to be implemented? The practice of genetic testing being highly controlled, some rules are then discussed. All over the paper, a reflection is proposed on what is allowed versus what is possible with reference to ethics.

  9. Stinging Insect Matching Game

    MedlinePlus

    ... for Kids ▸ Stinging Insect Matching Game Share | Stinging Insect Matching Game Stinging insects can ruin summer fun for those who are ... the difference between the different kinds of stinging insects in order to keep your summer safe and ...

  10. Jealousy Graphs: Structure and Complexity of Decentralized Stable Matching

    DTIC Science & Technology

    2013-01-01

    reaches a µ-stable matching. This means that in expectation it will take at most nlc 4(c+1) of these transitions total before all stable components...locally perfect on that stable component. Furthermore, this process needs to be repeated no more than nlc 4(c+1) times in expectation in order for all

  11. Phase- and group-matched nonlinear interactions mediated by multiple filamentation in Kerr media

    SciTech Connect

    Faccio, D.; Lotti, A.; Dubietis, A.; Tamosauskas, G.; Valiulis, G.; Piskarskas, A.; Polesana, P.; Di Trapani, P.; Couairon, A.

    2007-11-15

    Laser-pulse filamentation in Kerr media induced by a strongly elliptic input beam leads to breakup into a periodic array of filaments. In the plane of the filament array we observe strong Stokes and anti-Stokes emission at large angles. For 1 ps input pulses the measured angles are found to support two different phase-matching configurations: one nontransversally phase matched and the other perfectly phase matched. Shorter 200 fs pulses give rise to group-velocity-matched Raman conversion.

  12. Designing a perfect cornea: computational aspects

    NASA Astrophysics Data System (ADS)

    Rubinstein, Jacob; Wolansky, Gershon

    2002-12-01

    We analyze an algorithm for the design of a perfect cornea that exactly focuses a preselected object or a preselected wave front on the retina. The algorithm can be used, for example, in refractive surgery. We consider the sensitivity of the algorithm to various errors, including errors in the measurements of the aberrations, the original corneal topography and the ablation process.

  13. Maple Explorations, Perfect Numbers, and Mersenne Primes

    ERIC Educational Resources Information Center

    Ghusayni, B.

    2005-01-01

    Some examples from different areas of mathematics are explored to give a working knowledge of the computer algebra system Maple. Perfect numbers and Mersenne primes, which have fascinated people for a very long time and continue to do so, are studied using Maple and some questions are posed that still await answers.

  14. The Present Perfect in World Englishes

    ERIC Educational Resources Information Center

    Yao, Xinyue; Collins, Peter

    2012-01-01

    This paper reports on a comprehensive corpus-based study of regional and stylistic variation in the distribution of the English present perfect. The data represents ten English varieties of both the Inner Circle and Outer Circle, covering four major text types: conversation, news reportage, academic and fictional writing. The results are discussed…

  15. Perfect Phylogeny Problems with Missing Values.

    PubMed

    Kirkpatrick, Bonnie; Stevens, Kristian

    2014-01-01

    The perfect phylogeny problem is of central importance to both evolutionary biology and population genetics. Missing values are a common occurrence in both sequence and genotype data, but they make the problem of finding a perfect phylogeny NPhard even for binary characters. We introduce new and efficient perfect phylogeny algorithms for broad classes of binary and multistate data with missing values. Specifically, we address binary missing data consistent with the rich data hypothesis (RDH) introduced by Halperin and Karp and give an efficient algorithm for enumerating phylogenies. This algorithm is useful for computing the probability of data with missing values under the coalescent model. In addition, we use the partition intersection (PI) graph and chordal graph theory to generalize the RDH to multi-state characters with missing values. For a bounded number of states, we provide a fixed parameter tractable algorithm for the perfect phylogeny problem with missing data. Utilizing the PI graph, we are able to show that under multiple biologically motivated models for character data, our generalized RDH holds with high probability, and we evaluate our results with extensive empirical analysis.

  16. Mechanical Energy Changes in Perfectly Inelastic Collisions

    ERIC Educational Resources Information Center

    Mungan, Carl E.

    2013-01-01

    Suppose a block of mass "m"[subscript 1] traveling at speed "v"[subscript 1] makes a one-dimensional perfectly inelastic collision with another block of mass "m"[subscript 2]. What else does one need to know to calculate the fraction of the mechanical energy that is dissipated in the collision? (Contains 1 figure.)

  17. The Ambiguity of the English Present Perfect.

    ERIC Educational Resources Information Center

    Michaelis, Laura A.

    1994-01-01

    Examines grammatical and discourse-pragmatic reflexes of the existential and resultative readings of the English present perfect and presents negative and positive arguments regarding its ambiguity. It is suggested that the resultative verb represents a formal idiom and that mastery of aspectual grammar entails knowledge of form-meaning pairings.…

  18. Perfect Day: A Meditation about Teaching

    ERIC Educational Resources Information Center

    Valadez, Gilbert

    2004-01-01

    When asked by a student in a seminar recently if he could remember a perfect day teaching elementary school, the author writes memories of one he distinctly remembers because he gained new insight into teaching on that particular day. After returning to work following the devastating loss of a younger 19 year-old brother in a car crash, he resumed…

  19. Improving the time control of the Subboreal/Subatlantic transition in a Czech peat sequence by 14C wiggle-matching

    NASA Astrophysics Data System (ADS)

    Speranza, A.; van der Plicht, J.; van Geel, B.

    2000-11-01

    To achieve an optimal time-control for a late Subboreal to early Subatlantic peat sequence from Pančavská Louka in the Czech Republic, different strategies are applied to convert a series of radiocarbon dates into a calendar time-scale. The methods of selection and preparation of the samples for AMS 14C dating are presented. The results of calibrating single radiocarbon dates are compared with a 14C wiggle-match strategy. As the accumulation rate of the peat was not constant, the concentrations of arboreal pollen are used to estimate the accumulation rate changes and to correct for these changes. The resulting time-control represents the best solution for this peat sequence with the methods currently available.

  20. Uniform color space based on color matching

    NASA Astrophysics Data System (ADS)

    Liao, Shih-Fang; Yang, Tsung-Hsun; Lee, Cheng-Chung

    2007-09-01

    This research intends to explore with a uniform color space based on the CIE 1931 x-y chromatic coordinate system. The goal is to improve the non-uniformity of the CIE 1931 x-y chromaticity diagram such as to approach the human color sensation as possible; however, its simple methodology still can be kept. In spite of the existence of various kinds of the uniform color coordinate systems built up early (CIE u'-v', CIE Lab, CIE LUV, etc.), the establishment of a genuine uniform color space is actually still an important work both for the basic research in color science and the practical applications of colorimetry, especially for recent growing request in illumination engineering and in display technology. In this study, the MacAdam ellipses and the Munsell color chips are utilized for the comparison with the human color sensation. One specific linear transformation matrix is found for the CIE 1931 color matching functions (see manuscript) to become the novel uniform ones. With the aid of the optimization method, the transformation matrix can be easily discovered and makes the 25 MacAdam ellipses are similar to each other in the novel uniform color space. On the other hand, the perfectiveness of the equal-hue curves and the equal-chroma contours from the Mnusell color chips evaluates for the best optimization conditions among several different definitions for the similarity of all the MacAdam ellipses. Finally, the color difference between any two colors can be simply measured by the Euclidean distance in the novel uniform color space and is still fitted to the human color sensation.

  1. Matching a Distribution by Matching Quantiles Estimation

    PubMed Central

    Sgouropoulos, Nikolaos; Yao, Qiwei; Yastremiz, Claudia

    2015-01-01

    Motivated by the problem of selecting representative portfolios for backtesting counterparty credit risks, we propose a matching quantiles estimation (MQE) method for matching a target distribution by that of a linear combination of a set of random variables. An iterative procedure based on the ordinary least-squares estimation (OLS) is proposed to compute MQE. MQE can be easily modified by adding a LASSO penalty term if a sparse representation is desired, or by restricting the matching within certain range of quantiles to match a part of the target distribution. The convergence of the algorithm and the asymptotic properties of the estimation, both with or without LASSO, are established. A measure and an associated statistical test are proposed to assess the goodness-of-match. The finite sample properties are illustrated by simulation. An application in selecting a counterparty representative portfolio with a real dataset is reported. The proposed MQE also finds applications in portfolio tracking, which demonstrates the usefulness of combining MQE with LASSO. PMID:26692592

  2. Matching a Distribution by Matching Quantiles Estimation.

    PubMed

    Sgouropoulos, Nikolaos; Yao, Qiwei; Yastremiz, Claudia

    2015-04-03

    Motivated by the problem of selecting representative portfolios for backtesting counterparty credit risks, we propose a matching quantiles estimation (MQE) method for matching a target distribution by that of a linear combination of a set of random variables. An iterative procedure based on the ordinary least-squares estimation (OLS) is proposed to compute MQE. MQE can be easily modified by adding a LASSO penalty term if a sparse representation is desired, or by restricting the matching within certain range of quantiles to match a part of the target distribution. The convergence of the algorithm and the asymptotic properties of the estimation, both with or without LASSO, are established. A measure and an associated statistical test are proposed to assess the goodness-of-match. The finite sample properties are illustrated by simulation. An application in selecting a counterparty representative portfolio with a real dataset is reported. The proposed MQE also finds applications in portfolio tracking, which demonstrates the usefulness of combining MQE with LASSO.

  3. Renormalization group and perfect operators for stochastic differential equations.

    PubMed

    Hou, Q; Goldenfeld, N; McKane, A

    2001-03-01

    We develop renormalization group (RG) methods for solving partial and stochastic differential equations on coarse meshes. RG transformations are used to calculate the precise effect of small-scale dynamics on the dynamics at the mesh size. The fixed point of these transformations yields a perfect operator: an exact representation of physical observables on the mesh scale with minimal lattice artifacts. We apply the formalism to simple nonlinear models of critical dynamics, and show how the method leads to an improvement in the computational performance of Monte Carlo methods.

  4. Development of a Three Dimensional Perfectly Matched Layer for Transient Elasto-Dynamic Analyses

    DTIC Science & Technology

    2006-12-01

    dimensional analysis . Later Basu and Chopra(2004) [Ref. 14] extended the idea to a 2D transient, displacement-based, finite element (FE) method... Analysis of non-homogeneous/ anisotropic materials. • Analysis of non-linear wave phenomenon such as shock waves. The PML can be tuned to attenuate non...linear waves as well. • Conduct a time dependent analysis of an infinite waveguide using the tran- sient PML as an infinite boundary. • Examine the

  5. Text-Based Synchronous E-Learning and Dyslexia: Not Necessarily the Perfect Match!

    ERIC Educational Resources Information Center

    Woodfine, B. P.; Nunes, M. Baptista; Wright, D. J.

    2008-01-01

    The introduction, in the United Kingdom, of the Special Education Needs and Disabilities Act (SENDA) published and approved in 2001, has removed the exemptions given to educational institutions by the Disabilities Discrimination Act (DDA) of 1995. This applies to learning web sites and materials that must now undergo "reasonable…

  6. [Guide to perfect prescribing in Switzerland].

    PubMed

    Arnet, Isabelle; Hersberger, Kurt E

    2014-06-01

    An important initial step in the medication process is prescription writing. The more perfect it is, the more successfully can a therapy be performed. Imprecisions and missing information lead to unnecessary queries or to errors which are often randomly discovered during a later consultation. A "perfect prescription" serves every individual involved in the medication process. The prescription document contains the instructions for the patient, the pharmacist, the nurse, and other health professionals involved in the therapy. The prescription writing process is regulated by several laws and decrees which were enacted to assure the greatest possible drug safety. Deviations from the norm may be necessary in individual cases, which require an even more responsible prescribing and explicit indication.

  7. The undirected incomplete perfect phylogeny problem.

    PubMed

    Satya, Ravi Vijaya; Mukherjee, Amar

    2008-01-01

    The incomplete perfect phylogeny (IPP) problem and the incomplete perfect phylogeny haplotyping (IPPH) problem deal with constructing a phylogeny for a given set of haplotypes or genotypes with missing entries. The earlier approaches for both of these problems dealt with restricted versions of the problems, where the root is either available or can be trivially re-constructed from the data, or certain assumptions were made about the data. In this paper, we deal with the unrestricted versions of the problems, where the root of the phylogeny is neither available nor trivially recoverable from the data. Both IPP and IPPH problems have previously been proven to be NP-complete. Here, we present efficient enumerative algorithms that can handle practical instances of the problem. Empirical analysis on simulated data shows that the algorithms perform very well both in terms of speed and in terms accuracy of the recovered data.

  8. The erythrocyte ghost is a perfect osmometer.

    PubMed

    Kwant, W O; Seeman, P

    1970-02-01

    The osmotic swelling of intact erythrocytes in hypotonic solutions was measured using microhematocrit tubes, Van Allen tubes, and a calibrated Coulter counter. In agreement with earlier workers the intact cells did not behave as perfect osmometers, the cells swelling less than predicted by the Boyle-van't Hoff law. Erythrocyte ghosts were prepared from fresh intact erythrocytes by one-step hemolysis in 0.25% NaCl at an extremely dilute concentration of cells and the membranes were sealed at 37 degrees . The ghosts were mixed with NaCl solutions of different osmolarities and the MCV (mean cell volume) of the shrunken cells immediately monitored by a calibrated Coulter counter. It was found that the MCV values of the shrunken ghosts were accurately predicted by the Boyle-van't Hoff law. These results indicate that these erythrocyte ghosts behaved as perfect osmometers.

  9. Block Matching for Object Tracking

    SciTech Connect

    Gyaourova, A; Kamath, C; Cheung, S

    2003-10-13

    Models which describe road traffic patterns can be helpful in detection and/or prevention of uncommon and dangerous situations. Such models can be built by the use of motion detection algorithms applied to video data. Block matching is a standard technique for encoding motion in video compression algorithms. We explored the capabilities of the block matching algorithm when applied for object tracking. The goal of our experiments is two-fold: (1) to explore the abilities of the block matching algorithm on low resolution and low frame rate video and (2) to improve the motion detection performance by the use of different search techniques during the process of block matching. Our experiments showed that the block matching algorithm yields good object tracking results and can be used with high success on low resolution and low frame rate video data. We observed that different searching methods have small effect on the final results. In addition, we proposed a technique based on frame history, which successfully overcame false motion caused by small camera movements.

  10. Structured metal film as a perfect absorber.

    PubMed

    Xiong, Xiang; Jiang, Shang-Chi; Hu, Yu-Hui; Peng, Ru-Wen; Wang, Mu

    2013-08-07

    A new type of absorber, a four-tined fish-spear-like resonator (FFR), constructed by the two-photon polymerization process, is reported. An absorbance of more than 90% is experimentally realized and the resonance occurs in the space between the tines. Since a continuous layer of metallic thin film covers the structure, it is perfectly thermo- and electroconductive, which is the mostly desired feature for many applications.

  11. Mining a database of single amplified genomes from Red Sea brine pool extremophiles-improving reliability of gene function prediction using a profile and pattern matching algorithm (PPMA).

    PubMed

    Grötzinger, Stefan W; Alam, Intikhab; Ba Alawi, Wail; Bajic, Vladimir B; Stingl, Ulrich; Eppinger, Jörg

    2014-01-01

    Reliable functional annotation of genomic data is the key-step in the discovery of novel enzymes. Intrinsic sequencing data quality problems of single amplified genomes (SAGs) and poor homology of novel extremophile's genomes pose significant challenges for the attribution of functions to the coding sequences identified. The anoxic deep-sea brine pools of the Red Sea are a promising source of novel enzymes with unique evolutionary adaptation. Sequencing data from Red Sea brine pool cultures and SAGs are annotated and stored in the Integrated Data Warehouse of Microbial Genomes (INDIGO) data warehouse. Low sequence homology of annotated genes (no similarity for 35% of these genes) may translate into false positives when searching for specific functions. The Profile and Pattern Matching (PPM) strategy described here was developed to eliminate false positive annotations of enzyme function before progressing to labor-intensive hyper-saline gene expression and characterization. It utilizes InterPro-derived Gene Ontology (GO)-terms (which represent enzyme function profiles) and annotated relevant PROSITE IDs (which are linked to an amino acid consensus pattern). The PPM algorithm was tested on 15 protein families, which were selected based on scientific and commercial potential. An initial list of 2577 enzyme commission (E.C.) numbers was translated into 171 GO-terms and 49 consensus patterns. A subset of INDIGO-sequences consisting of 58 SAGs from six different taxons of bacteria and archaea were selected from six different brine pool environments. Those SAGs code for 74,516 genes, which were independently scanned for the GO-terms (profile filter) and PROSITE IDs (pattern filter). Following stringent reliability filtering, the non-redundant hits (106 profile hits and 147 pattern hits) are classified as reliable, if at least two relevant descriptors (GO-terms and/or consensus patterns) are present. Scripts for annotation, as well as for the PPM algorithm, are available

  12. Mining a database of single amplified genomes from Red Sea brine pool extremophiles—improving reliability of gene function prediction using a profile and pattern matching algorithm (PPMA)

    PubMed Central

    Grötzinger, Stefan W.; Alam, Intikhab; Ba Alawi, Wail; Bajic, Vladimir B.; Stingl, Ulrich; Eppinger, Jörg

    2014-01-01

    Reliable functional annotation of genomic data is the key-step in the discovery of novel enzymes. Intrinsic sequencing data quality problems of single amplified genomes (SAGs) and poor homology of novel extremophile's genomes pose significant challenges for the attribution of functions to the coding sequences identified. The anoxic deep-sea brine pools of the Red Sea are a promising source of novel enzymes with unique evolutionary adaptation. Sequencing data from Red Sea brine pool cultures and SAGs are annotated and stored in the Integrated Data Warehouse of Microbial Genomes (INDIGO) data warehouse. Low sequence homology of annotated genes (no similarity for 35% of these genes) may translate into false positives when searching for specific functions. The Profile and Pattern Matching (PPM) strategy described here was developed to eliminate false positive annotations of enzyme function before progressing to labor-intensive hyper-saline gene expression and characterization. It utilizes InterPro-derived Gene Ontology (GO)-terms (which represent enzyme function profiles) and annotated relevant PROSITE IDs (which are linked to an amino acid consensus pattern). The PPM algorithm was tested on 15 protein families, which were selected based on scientific and commercial potential. An initial list of 2577 enzyme commission (E.C.) numbers was translated into 171 GO-terms and 49 consensus patterns. A subset of INDIGO-sequences consisting of 58 SAGs from six different taxons of bacteria and archaea were selected from six different brine pool environments. Those SAGs code for 74,516 genes, which were independently scanned for the GO-terms (profile filter) and PROSITE IDs (pattern filter). Following stringent reliability filtering, the non-redundant hits (106 profile hits and 147 pattern hits) are classified as reliable, if at least two relevant descriptors (GO-terms and/or consensus patterns) are present. Scripts for annotation, as well as for the PPM algorithm, are available

  13. Solute drag on perfect and extended dislocations

    NASA Astrophysics Data System (ADS)

    Sills, R. B.; Cai, W.

    2016-04-01

    The drag force exerted on a moving dislocation by a field of mobile solutes is studied in the steady state. The drag force is numerically calculated as a function of the dislocation velocity for both perfect and extended dislocations. The sensitivity of the non-dimensionalized force-velocity curve to the various controlling parameters is assessed, and an approximate analytical force-velocity expression is given. A non-dimensional parameter S characterizing the strength of the solute-dislocation interaction, the background solute fraction ?, and the dislocation character angle ?, are found to have the strongest influence on the force-velocity curve. Within the model considered here, a perfect screw dislocation experiences no solute drag, but an extended screw dislocation experiences a non-zero drag force that is about 10 to 30% of the drag on an extended edge dislocation. The solutes can change the spacing between the Shockley partials in both stationary and moving extended dislocations, even when the stacking fault energy remains unaltered. Under certain conditions, the solutes destabilize an extended dislocation by either collapsing it into a perfect dislocation or causing the partials to separate unboundedly. It is proposed that the latter instability may lead to the formation of large faulted areas and deformation twins in low stacking fault energy materials containing solutes, consistent with experimental observations of copper and stainless steel containing hydrogen.

  14. Optimal Feedback Controlled Assembly of Perfect Crystals.

    PubMed

    Tang, Xun; Rupp, Bradley; Yang, Yuguang; Edwards, Tara D; Grover, Martha A; Bevan, Michael A

    2016-07-26

    Perfectly ordered states are targets in diverse molecular to microscale systems involving, for example, atomic clusters, protein folding, protein crystallization, nanoparticle superlattices, and colloidal crystals. However, there is no obvious approach to control the assembly of perfectly ordered global free energy minimum structures; near-equilibrium assembly is impractically slow, and faster out-of-equilibrium processes generally terminate in defective states. Here, we demonstrate the rapid and robust assembly of perfect crystals by navigating kinetic bottlenecks using closed-loop control of electric field mediated crystallization of colloidal particles. An optimal policy is computed with dynamic programming using a reaction coordinate based dynamic model. By tracking real-time stochastic particle configurations and adjusting applied fields via feedback, the evolution of unassembled particles is guided through polycrystalline states into single domain crystals. This approach to controlling the assembly of a target structure is based on general principles that make it applicable to a broad range of processes from nano- to microscales (where tuning a global thermodynamic variable yields temporal control over thermal sampling of different states via their relative free energies).

  15. Broadband gradient impedance matching using an acoustic metamaterial for ultrasonic transducers.

    PubMed

    Li, Zheng; Yang, Dan-Qing; Liu, Shi-Lei; Yu, Si-Yuan; Lu, Ming-Hui; Zhu, Jie; Zhang, Shan-Tao; Zhu, Ming-Wei; Guo, Xia-Sheng; Wu, Hao-Dong; Wang, Xin-Long; Chen, Yan-Feng

    2017-02-17

    High-quality broadband ultrasound transducers yield superior imaging performance in biomedical ultrasonography. However, proper design to perfectly bridge the energy between the active piezoelectric material and the target medium over the operating spectrum is still lacking. Here, we demonstrate a new anisotropic cone-structured acoustic metamaterial matching layer that acts as an inhomogeneous material with gradient acoustic impedance along the ultrasound propagation direction. When sandwiched between the piezoelectric material unit and the target medium, the acoustic metamaterial matching layer provides a broadband window to support extraordinary transmission of ultrasound over a wide frequency range. We fabricated the matching layer by etching the peeled silica optical fibre bundles with hydrofluoric acid solution. The experimental measurement of an ultrasound transducer equipped with this acoustic metamaterial matching layer shows that the corresponding -6 dB bandwidth is able to reach over 100%. This new material fully enables new high-end piezoelectric materials in the construction of high-performance ultrasound transducers and probes, leading to considerably improved resolutions in biomedical ultrasonography and compact harmonic imaging systems.

  16. Broadband gradient impedance matching using an acoustic metamaterial for ultrasonic transducers

    PubMed Central

    Li, Zheng; Yang, Dan-Qing; Liu, Shi-Lei; Yu, Si-Yuan; Lu, Ming-Hui; Zhu, Jie; Zhang, Shan-Tao; Zhu, Ming-Wei; Guo, Xia-Sheng; Wu, Hao-Dong; Wang, Xin-Long; Chen, Yan-Feng

    2017-01-01

    High-quality broadband ultrasound transducers yield superior imaging performance in biomedical ultrasonography. However, proper design to perfectly bridge the energy between the active piezoelectric material and the target medium over the operating spectrum is still lacking. Here, we demonstrate a new anisotropic cone-structured acoustic metamaterial matching layer that acts as an inhomogeneous material with gradient acoustic impedance along the ultrasound propagation direction. When sandwiched between the piezoelectric material unit and the target medium, the acoustic metamaterial matching layer provides a broadband window to support extraordinary transmission of ultrasound over a wide frequency range. We fabricated the matching layer by etching the peeled silica optical fibre bundles with hydrofluoric acid solution. The experimental measurement of an ultrasound transducer equipped with this acoustic metamaterial matching layer shows that the corresponding −6 dB bandwidth is able to reach over 100%. This new material fully enables new high-end piezoelectric materials in the construction of high-performance ultrasound transducers and probes, leading to considerably improved resolutions in biomedical ultrasonography and compact harmonic imaging systems. PMID:28211510

  17. Broadband gradient impedance matching using an acoustic metamaterial for ultrasonic transducers

    NASA Astrophysics Data System (ADS)

    Li, Zheng; Yang, Dan-Qing; Liu, Shi-Lei; Yu, Si-Yuan; Lu, Ming-Hui; Zhu, Jie; Zhang, Shan-Tao; Zhu, Ming-Wei; Guo, Xia-Sheng; Wu, Hao-Dong; Wang, Xin-Long; Chen, Yan-Feng

    2017-02-01

    High-quality broadband ultrasound transducers yield superior imaging performance in biomedical ultrasonography. However, proper design to perfectly bridge the energy between the active piezoelectric material and the target medium over the operating spectrum is still lacking. Here, we demonstrate a new anisotropic cone-structured acoustic metamaterial matching layer that acts as an inhomogeneous material with gradient acoustic impedance along the ultrasound propagation direction. When sandwiched between the piezoelectric material unit and the target medium, the acoustic metamaterial matching layer provides a broadband window to support extraordinary transmission of ultrasound over a wide frequency range. We fabricated the matching layer by etching the peeled silica optical fibre bundles with hydrofluoric acid solution. The experimental measurement of an ultrasound transducer equipped with this acoustic metamaterial matching layer shows that the corresponding ‑6 dB bandwidth is able to reach over 100%. This new material fully enables new high-end piezoelectric materials in the construction of high-performance ultrasound transducers and probes, leading to considerably improved resolutions in biomedical ultrasonography and compact harmonic imaging systems.

  18. Ontology Matching Across Domains

    DTIC Science & Technology

    2010-05-01

    matching include GMO [1], Anchor-Prompt [2], and Similarity Flooding [3]. GMO is an iterative structural matcher, which uses RDF bipartite graphs to...AFRL under contract# FA8750-09-C-0058. References [1] Hu, W., Jian, N., Qu, Y., Wang, Y., “ GMO : a graph matching for ontologies”, in: Proceedings of

  19. DOE Matching Grant Program

    SciTech Connect

    Dr Marvin Adams

    2002-03-01

    OAK 270 - The DOE Matching Grant Program provided $50,000.00 to the Dept of N.E. at TAMU, matching a gift of $50,000.00 from TXU Electric. The $100,000.00 total was spent on scholarships, departmental labs, and computing network.

  20. Improving late Holocene radiocarbon-based chronologies by matching paleomagnetic secular variations to geomagnetic field models - Examples from Nam Co (Tibet) and Lake Kalimpaa (Sulawesi)

    NASA Astrophysics Data System (ADS)

    Haberzettl, T.; Kasper, T.; St-Onge, G.; Behling, H.; Daut, G.; Doberschütz, S.; Kirleis, W.; Mäusbacher, R.; Nowaczyk, N.

    2010-12-01

    were chosen for age-depth modeling and a linear interpolation was applied. Subsequently, inclination, declination and intensity were compared to the CALS3k.3 model also showing an excellent match from ~1350 cal BP to the present. Although, the age-depth models of both lakes are conservative, comparisons of paleomagnetic data with geomagnetic spherical harmonic models support this approach. This leads to the conclusion that the presented chronologies are suited for further paleoenvironmental investigations. This is important as both areas lack well-dated records. On the other hand, our data also support the validity of the CALS-models for the past ~4000 and ~1350 cal BP on the Tibetan Plateau and Indonesia, where paleomagnetic data are very scarce.

  1. An almost 'perfectly' diffuse, 'perfect' reflector for far-infrared reflectance calibration

    NASA Technical Reports Server (NTRS)

    Smith, Sheldon M.

    1993-01-01

    Specular and diffuse reflectance measurements made near normal incidence of two very rough, solid aluminum surfaces are presented for the wavelength range from 2.2 to 512 microns. The diffuse measurements made at nonspecular angles by two different detectors indicate that between 33 and 201 microns the reflectance of one surface is nearly Lambertian (isotropic) with a bidirectional reflectance distribution function (BRDF) value within 32 percent of the theoretical value of (1/pi)/sr for a perfectly diffuse, perfect reflector. Photometric reflectance spectra at the specular angle show that between 6.9 and 100 microns the specular BRDF of these surfaces is within 5 percent of the theoretical value of (1/pi)/sr. At longer wavelengths of 235, 320, and 512 microns the specular reflectance rapidly departs from that of a perfectly diffuse, perfect reflector. The two samples studied have rms surface roughnesses of 44 and 60 microns. A durable metal surface with these near perfect reflectance characteristics can be advantageously used in the FIR as a black-body source, the interior surface of an integrating sphere, and most especially as an absolute calibration standard. BRDF measurements at 40 deg incidence, though still highly diffuse, show a significant departure from Lambertian reflectance.

  2. The Perfect Aspect as a State of Being.

    ERIC Educational Resources Information Center

    Moy, Raymond H.

    English as second language (ESL) learners often avoid using the present perfect or use it improperly. In contrast with native speakers of English sampled from newspaper editorials, of whom 75 percent used the present perfect, only 22 percent of ESL college students used the present perfect correctly. This avoidance is due in part to lack of…

  3. Designing perfect linear polarization converters using perfect electric and magnetic conducting surfaces

    PubMed Central

    Zhou, Gaochao; Tao, Xudong; Shen, Ze; Zhu, Guanghao; Jin, Biaobing; Kang, Lin; Xu, Weiwei; Chen, Jian; Wu, Peiheng

    2016-01-01

    We propose a kind of general framework for the design of a perfect linear polarization converter that works in the transmission mode. Using an intuitive picture that is based on the method of bi-directional polarization mode decomposition, it is shown that when the device under consideration simultaneously possesses two complementary symmetry planes, with one being equivalent to a perfect electric conducting surface and the other being equivalent to a perfect magnetic conducting surface, linear polarization conversion can occur with an efficiency of 100% in the absence of absorptive losses. The proposed framework is validated by two design examples that operate near 10 GHz, where the numerical, experimental and analytic results are in good agreements. PMID:27958313

  4. Sublithographic Architecture: Shifting the Responsibility for Perfection

    NASA Astrophysics Data System (ADS)

    Dehon, A.

    In the past, processing had orders of magnitude between devices and atoms (e.g., with silicon atom lattice spacing around 0.5 nm, a minimum size feature was roughly 2000 atoms wide when we had 1 μm feature sizes). It was the process engineer's job to craft this large collection of atoms into "perfect" devices. The circuit designer and architect could then design systems knowing the process engineer would always give them a set of perfect devices. As we continue to shrink our devices, we no longer have orders of magnitude between the devices and the atoms. As a result, the circuit designers and architects are beginning to work within a similar realm of atoms. Consequently, they must assume some of the responsibilities for dealing with atomic-scale imperfections and uncertainty. This demands a significant shift in our abstraction hierarchy, the responsibilities and expectations at each level in this hierarchy, our fabrication techniques, our testing strategies, and our approaches to design for these atomic-scale computing systems.

  5. Cognitive Levels Matching.

    ERIC Educational Resources Information Center

    Brooks, Martin; And Others

    1983-01-01

    The Cognitive Levels Matching Project trains teachers to guide students' skill acquisition and problem-solving processes by assessing students' cognitive levels and adapting their teaching materials accordingly. (MLF)

  6. Project Matching Initiative

    EPA Pesticide Factsheets

    The Green Power Partnership's Project Matching initiative works to connect green power users with new, not-yet-built renewable energy projects that may align with their energy, environmental, and financial objectives.

  7. The molecular matching problem

    NASA Technical Reports Server (NTRS)

    Kincaid, Rex K.

    1993-01-01

    Molecular chemistry contains many difficult optimization problems that have begun to attract the attention of optimizers in the Operations Research community. Problems including protein folding, molecular conformation, molecular similarity, and molecular matching have been addressed. Minimum energy conformations for simple molecular structures such as water clusters, Lennard-Jones microclusters, and short polypeptides have dominated the literature to date. However, a variety of interesting problems exist and we focus here on a molecular structure matching (MSM) problem.

  8. Fast image matching algorithm based on projection characteristics

    NASA Astrophysics Data System (ADS)

    Zhou, Lijuan; Yue, Xiaobo; Zhou, Lijun

    2011-06-01

    Based on analyzing the traditional template matching algorithm, this paper identified the key factors restricting the speed of matching and put forward a brand new fast matching algorithm based on projection. Projecting the grayscale image, this algorithm converts the two-dimensional information of the image into one-dimensional one, and then matches and identifies through one-dimensional correlation, meanwhile, because of normalization has been done, when the image brightness or signal amplitude increasing in proportion, it could also perform correct matching. Experimental results show that the projection characteristics based image registration method proposed in this article could greatly improve the matching speed, which ensuring the matching accuracy as well.

  9. DOE Matching Grant Program

    SciTech Connect

    Tsoukalas, L.

    2002-12-31

    Funding used to support a portion of the Nuclear Engineering Educational Activities. Upgrade of teaching labs, student support to attend professional conferences, salary support for graduate students. The US Department of Energy (DOE) has funded Purdue University School of Nuclear Engineering during the period of five academic years covered in this report starting in the academic year 1996-97 and ending in the academic year 2000-2001. The total amount of funding for the grant received from DOE is $416K. In the 1990's, Nuclear Engineering Education in the US experienced a significant slow down. Student enrollment, research support, number of degrees at all levels (BS, MS, and PhD), number of accredited programs, University Research and Training Reactors, all went through a decline to alarmingly low levels. Several departments closed down, while some were amalgamated with other academic units (Mechanical Engineering, Chemical Engineering, etc). The School of Nuclear Engineering at Purdue University faced a major challenge when in the mid 90's our total undergraduate enrollment for the Sophomore, Junior and Senior Years dropped in the low 30's. The DOE Matching Grant program greatly strengthened Purdue's commitment to the Nuclear Engineering discipline and has helped to dramatically improve our undergraduate and graduate enrollment, attract new faculty and raise the School of Nuclear Engineering status within the University and in the National scene (our undergraduate enrollment has actually tripled and stands at an all time high of over 90 students; total enrollment currently exceeds 110 students). In this final technical report we outline and summarize how the grant was expended at Purdue University.

  10. Innovative Writing Instruction: Practice Makes Perfect! Realizing Classrooms as "Landscapes of Learning," Not Places of Perfection

    ERIC Educational Resources Information Center

    Ozier, Lance

    2011-01-01

    Pressure for students to produce writing perfection in the classroom often eclipses the emphasis placed on the need for students to practice writing. Occasions for students to choose, challenge, and reflect--to actually risk risking--are too often absent from conversations among students and teachers in countless English classrooms. Tom Romano…

  11. PUMA: The Positional Update and Matching Algorithm

    NASA Astrophysics Data System (ADS)

    Line, J. L. B.; Webster, R. L.; Pindor, B.; Mitchell, D. A.; Trott, C. M.

    2017-01-01

    We present new software to cross-match low-frequency radio catalogues: the Positional Update and Matching Algorithm. The Positional Update and Matching Algorithm combines a positional Bayesian probabilistic approach with spectral matching criteria, allowing for confusing sources in the matching process. We go on to create a radio sky model using Positional Update and Matching Algorithm based on the Murchison Widefield Array Commissioning Survey, and are able to automatically cross-match 98.5% of sources. Using the characteristics of this sky model, we create simple simulated mock catalogues on which to test the Positional Update and Matching Algorithm, and find that Positional Update and Matching Algorithm can reliably find the correct spectral indices of sources, along with being able to recover ionospheric offsets. Finally, we use this sky model to calibrate and remove foreground sources from simulated interferometric data, generated using OSKAR (the Oxford University visibility generator). We demonstrate that there is a substantial improvement in foreground source removal when using higher frequency and higher resolution source positions, even when correcting positions by an average of 0.3 arcmin given a synthesised beam-width of 2.3 arcmin.

  12. Matching forensic sketches to mug shot photos.

    PubMed

    Klare, Brendan F; Li, Zhifeng; Jain, Anil K

    2011-03-01

    The problem of matching a forensic sketch to a gallery of mug shot images is addressed in this paper. Previous research in sketch matching only offered solutions to matching highly accurate sketches that were drawn while looking at the subject (viewed sketches). Forensic sketches differ from viewed sketches in that they are drawn by a police sketch artist using the description of the subject provided by an eyewitness. To identify forensic sketches, we present a framework called local feature-based discriminant analysis (LFDA). In LFDA, we individually represent both sketches and photos using SIFT feature descriptors and multiscale local binary patterns (MLBP). Multiple discriminant projections are then used on partitioned vectors of the feature-based representation for minimum distance matching. We apply this method to match a data set of 159 forensic sketches against a mug shot gallery containing 10,159 images. Compared to a leading commercial face recognition system, LFDA offers substantial improvements in matching forensic sketches to the corresponding face images. We were able to further improve the matching performance using race and gender information to reduce the target gallery size. Additional experiments demonstrate that the proposed framework leads to state-of-the-art accuracys when matching viewed sketches.

  13. A perfect launch viewed across Banana Creek

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Billows of smoke and steam surround Space Shuttle Discovery as it lifts off from Launch Pad 39A on mission STS-92 to the International Space Station. The perfect on-time liftoff occurred at 7:17 p.m. EDT, sending a crew of seven on the 100th launch in the history of the Shuttle program. Discovery carries a payload that includes the Integrated Truss Structure Z-1, first of 10 trusses that will form the backbone of the Space Station, and the third Pressurized Mating Adapter that will provide a Shuttle docking port for solar array installation on the sixth Station flight and Lab installation on the seventh Station flight. Discovery's landing is expected Oct. 22 at 2:10 p.m. EDT.

  14. Recent Results from RHIC: The Perfect Liquid

    SciTech Connect

    Westfall, Gary

    2006-07-19

    In the past two years we have witnessed a leap forward in the understanding high temperature, high density, and strongly interacting matter produced in ultra-relativistic heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. Combining measurements of Au+Au, d+Au, and p+p collisions at energies up to 200 GeV per nucleon pair in the center of mass frame, the four RHIC experimental groups, STAR, PHENIX, PHOBOS, and BRAHMS, have produced impressive experimental evidence for the existence of a new form of matter. In this Colloquium, I will present an overview of recent experimental results from RHIC including evidence for thermalization, hydrodynamic behavior of a perfect fluid, the partonic origin of flow, and jet suppression. These measurements point to the observation of a hot, dense, strongly interacting matter produced in central Au+Au collisions at the highest available energies.

  15. A perfect launch viewed across Banana Creek

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Space Shuttle Discovery seems to burst forth from a pillow of smoke as it lifts off from Launch Pad 39A on mission STS-92 to the International Space Station. The brilliant light from the solid rocket booster flames is reflected in nearby water. The perfect on-time liftoff occurred at 7:17 p.m. EDT, sending a crew of seven on the 100th launch in the history of the Shuttle program. Discovery carries a payload that includes the Integrated Truss Structure Z-1, first of 10 trusses that will form the backbone of the Space Station, and the third Pressurized Mating Adapter that will provide a Shuttle docking port for solar array installation on the sixth Station flight and Lab installation on the seventh Station flight. Discovery's landing is expected Oct. 22 at 2:10 p.m. EDT.

  16. Electromagnetic Detection of a Perfect Carpet Cloak

    NASA Astrophysics Data System (ADS)

    Shi, Xihang; Gao, Fei; Lin, Xiao; Zhang, Baile

    2015-05-01

    It has been shown that a spherical invisibility cloak originally proposed by Pendry et al. can be electromagnetically detected by shooting a charged particle through it, whose underlying mechanism stems from the asymmetry of transformation optics applied to motions of photons and charges [PRL 103, 243901 (2009)]. However, the conceptual three-dimensional invisibility cloak that exactly follows specifications of transformation optics is formidably difficult to implement, while the simplified cylindrical cloak that has been experimentally realized is inherently visible. On the other hand, the recent carpet cloak model has acquired remarkable experimental development, including a recently demonstrated full-parameter carpet cloak without any approximation in the required constitutive parameters. In this paper, we numerically investigate the electromagnetic radiation from a charged particle passing through a perfect carpet cloak and propose an experimentally verifiable model to demonstrate symmetry breaking of transformation optics.

  17. An approach towards a perfect thermal diffuser

    PubMed Central

    Vemuri, Krishna P.; Bandaru, Prabhakar R.

    2016-01-01

    A method for the most efficient removal of heat, through an anisotropic composite, is proposed. It is shown that a rational placement of constituent materials, in the radial and the azimuthal directions, at a given point in the composite yields a uniform temperature distribution in spherical diffusers. Such arrangement is accompanied by a very significant reduction of the source temperature, in principle, to infinitesimally above the ambient temperature and forms the basis for the design of a perfect thermal diffuser with maximal heat dissipation. Orders of magnitude enhanced performance, compared to that obtained through the use of a diffuser constituted from a single material with isotropic thermal conductivity has been observed and the analytical principles underlying the design were validated through extensive computational simulations. PMID:27404569

  18. Do musicians with perfect pitch have more autism traits than musicians without perfect pitch? An empirical study.

    PubMed

    Dohn, Anders; Garza-Villarreal, Eduardo A; Heaton, Pamela; Vuust, Peter

    2012-01-01

    Perfect pitch, also known as absolute pitch (AP), refers to the rare ability to identify or produce a musical tone correctly without the benefit of an external reference. AP is often considered to reflect musical giftedness, but it has also been associated with certain disabilities due to increased prevalence of AP in individuals with sensory and developmental disorders. Here, we determine whether individual autistic traits are present in people with AP. We quantified subclinical levels of autism traits using the Autism-Spectrum Quotient (AQ) in three matched groups of subjects: 16 musicians with AP (APs), 18 musicians without AP (non-APs), and 16 non-musicians. In addition, we measured AP ability by a pitch identification test with sine wave tones and piano tones. We found a significantly higher degree of autism traits in APs than in non-APs and non-musicians, and autism scores were significantly correlated with pitch identification scores (r = .46, p = .003). However, our results showed that APs did not differ from non-APs on diagnostically crucial social and communicative domain scores and their total AQ scores were well below clinical thresholds for autism. Group differences emerged on the imagination and attention switching subscales of the AQ. Thus, whilst these findings do link AP with autism, they also show that AP ability is most strongly associated with personality traits that vary widely within the normal population.

  19. LensPerfect Analysis of Abell 1689

    NASA Astrophysics Data System (ADS)

    Coe, Dan A.

    2007-12-01

    I present the first massmap to perfectly reproduce the position of every gravitationally-lensed multiply-imaged galaxy detected to date in ACS images of Abell 1689. This massmap was obtained using a powerful new technique made possible by a recent advance in the field of Mathematics. It is the highest resolution assumption-free Dark Matter massmap to date, with the resolution being limited only by the number of multiple images detected. We detect 8 new multiple image systems and identify multiple knots in individual galaxies to constrain a grand total of 168 knots within 135 multiple images of 42 galaxies. No assumptions are made about mass tracing light, and yet the brightest visible structures in A1689 are reproduced in our massmap, a few with intriguing positional offsets. Our massmap probes radii smaller than that resolvable in current Dark Matter simulations of galaxy clusters. And at these radii, we observe slight deviations from the NFW and Sersic profiles which describe simulated Dark Matter halos so well. While we have demonstrated that our method is able to recover a known input massmap (to limited resolution), further tests are necessary to determine the uncertainties of our mass profile and positions of massive subclumps. I compile the latest weak lensing data from ACS, Subaru, and CFHT, and attempt to fit a single profile, either NFW or Sersic, to both the observed weak and strong lensing. I confirm the finding of most previous authors, that no single profile fits extremely well to both simultaneously. Slight deviations are revealed, with the best fits slightly over-predicting the mass profile at both large and small radius. Our easy-to-use software, called LensPerfect, will be made available soon. This research was supported by the European Commission Marie Curie International Reintegration Grant 017288-BPZ and the PNAYA grant AYA2005-09413-C02.

  20. Self-Impedance-Matched Hall-Effect Gyrators and Circulators

    NASA Astrophysics Data System (ADS)

    Bosco, S.; Haupt, F.; DiVincenzo, D. P.

    2017-02-01

    We present a model study of an alternative implementation of a two-port Hall-effect microwave gyrator. Our setup involves three electrodes, one of which acts as a common ground for the others. Based on the capacitive-coupling model of Viola and DiVincenzo, we analyze the performance of the device and we predict that ideal gyration can be achieved at specific frequencies. Interestingly, the impedance of the three-terminal gyrator can be made arbitrarily small for certain coupling strengths, so that no auxiliary impedance matching is required. Although the bandwidth of the device shrinks as the impedance decreases, it can be improved by reducing the magnetic field; it can be realistically increased up to 150 MHz at 50 Ω by working at the filling factor ν =10 . We also examine the effects of the parasitic capacitive coupling between electrodes and we find that, although, in general, they strongly influence the response of device, their effect is negligible at low impedance. Finally, we analyze an interferometric implementation of a circulator, which incorporates the gyrator in a Mach-Zender-like construction. Perfect circulation in both directions can be achieved, depending on frequency and on the details of the interferometer.

  1. Total transmission of airborne sound by impedance-matched ultra-thin metasurfaces

    NASA Astrophysics Data System (ADS)

    Tang, Weipeng; Ren, Chunyu

    2017-03-01

    Acoustic labyrinthine metamaterials are particularly effective for constructing acoustic metasurfaces owing to their extreme refractive index. However, an evident drawback of these coiling-up structures is their large impedance mismatch with incident waves, causing less than optimal results. In this paper, we show that the intractable impedance mismatching problem can be solved by spatially tailoring the geometry of the labyrinthine metamaterial units and hence their effective constitutive parameters. These optimized units simultaneously exhibit a tunable refractive index up to 7 and a perfect impedance match with air; thus, as building units, they show potential for improving the performance of acoustic metasurface-based applications. Applying these deep-subwavelength units in anomalous refraction and an acoustic antenna, we demonstrate that the new optimized acoustic labyrinthine metamaterial-based design scheme shows extraordinary beam-steering effects, and more importantly, it provides extremely high transmission efficiency with a smaller size than existing designs.

  2. A New Approach for Semantic Web Matching

    NASA Astrophysics Data System (ADS)

    Zamanifar, Kamran; Heidary, Golsa; Nematbakhsh, Naser; Mardukhi, Farhad

    In this work we propose a new approach for semantic web matching to improve the performance of Web Service replacement. Because in automatic systems we should ensure the self-healing, self-configuration, self-optimization and self-management, all services should be always available and if one of them crashes, it should be replaced with the most similar one. Candidate services are advertised in Universal Description, Discovery and Integration (UDDI) all in Web Ontology Language (OWL). By the help of bipartite graph, we did the matching between the crashed service and a Candidate one. Then we chose the best service, which had the maximum rate of matching. In fact we compare two services' functionalities and capabilities to see how much they match. We found that the best way for matching two web services, is comparing the functionalities of them.

  3. Conformal and traversable wormholes with monopole and perfect fluid in f(R)-gravity

    NASA Astrophysics Data System (ADS)

    Taşer, Doǧukan; Doǧru, Melis Ulu

    2016-10-01

    We investigate spherically symmetric spacetime filled with global monopole and perfect fluid in f(R)-gravity. We consider field equations of f(R)-gravity in order to understand the global monopole and the perfect fluid curve to the spacetime. It has taken advantages of conformal symmetry properties of the spacetime to solve these equations. The obtained solutions are improved in case of phantom energy. It is shown that obtained f(R) function is consistent with well-known models of the modified gravity. Also, it is examined whether the obtained solutions support a traversable wormhole geometry. Obtained results of the solutions have been concluded.

  4. Cross-matching within the Chandra Source Catalog

    NASA Astrophysics Data System (ADS)

    Rots, Arnold H.; Burke, Douglas J.; Civano, Francesca; Hain, Roger; Nguyen, Dan

    2017-01-01

    Cross-matching among overlapping source detections in the development of the Chandra Source Catalog (CSC) presents considerable challenges, since the Point Spread Function (PSF) of the Chandra X-ray Observatory varies significantly over the field of view. For the production of the second release of the CSC we have developed a cross-match tool that is based on the Bayesian algorithms by Budavari, Heinis, and Szalay (ApJ 679, 301 and 705, 739), making use of the error ellipses for the derived positions of the detections.However, calculating match probabilities only on the basis of error ellipses breaks down when the PSFs are significantly different. This is an issue that is not commonly addressed in cross-match tools. We have applied a satisfactory modification to the algorithm that, although not perfect, ameliorates the issue for the vast majority of such cases.A separate issue is that as the number of overlapping detections increases, the number of matches to be considered increases at an alarming rate, requiring procedural adjustments to ensure that the cross-matching finishes within a Hubble time.We intend to make the tool available as a general purpose cross-match engine for calculating match probabilities between sources in multiple catalogs simultaneously.This work has been supported by NASA under contract NAS 8-03060 to the Smithsonian Astrophysical Observatory for operation of the Chandra X-ray Center.

  5. Results from the VALUE perfect predictor experiment: process-based evaluation

    NASA Astrophysics Data System (ADS)

    Maraun, Douglas; Soares, Pedro; Hertig, Elke; Brands, Swen; Huth, Radan; Cardoso, Rita; Kotlarski, Sven; Casado, Maria; Pongracz, Rita; Bartholy, Judit

    2016-04-01

    Until recently, the evaluation of downscaled climate model simulations has typically been limited to surface climatologies, including long term means, spatial variability and extremes. But these aspects are often, at least partly, tuned in regional climate models to match observed climate. The tuning issue is of course particularly relevant for bias corrected regional climate models. In general, a good performance of a model for these aspects in present climate does therefore not imply a good performance in simulating climate change. It is now widely accepted that, to increase our condidence in climate change simulations, it is necessary to evaluate how climate models simulate relevant underlying processes. In other words, it is important to assess whether downscaling does the right for the right reason. Therefore, VALUE has carried out a broad process-based evaluation study based on its perfect predictor experiment simulations: the downscaling methods are driven by ERA-Interim data over the period 1979-2008, reference observations are given by a network of 85 meteorological stations covering all European climates. More than 30 methods participated in the evaluation. In order to compare statistical and dynamical methods, only variables provided by both types of approaches could be considered. This limited the analysis to conditioning local surface variables on variables from driving processes that are simulated by ERA-Interim. We considered the following types of processes: at the continental scale, we evaluated the performance of downscaling methods for positive and negative North Atlantic Oscillation, Atlantic ridge and blocking situations. At synoptic scales, we considered Lamb weather types for selected European regions such as Scandinavia, the United Kingdom, the Iberian Pensinsula or the Alps. At regional scales we considered phenomena such as the Mistral, the Bora or the Iberian coastal jet. Such process-based evaluation helps to attribute biases in surface

  6. Metasurface perfect absorber based on guided resonance of a photonic hypercrystal

    NASA Astrophysics Data System (ADS)

    Chang, You-Chia; Kildishev, Alexander V.; Narimanov, Evgenii E.; Norris, Theodore B.

    2016-10-01

    By exploiting the guided resonance of a photonic hypercrystal—a periodic structure that combines the properties of hyperbolic materials and photonic crystals—we numerically demonstrate a perfect absorber consisting of a photonic hypercrystal slab, a dielectric spacer, and a back reflector. The guided resonance of the photonic hypercrystal slab creates a field enhancement and confinement within a deep subwavelength thickness; therefore, the ultrathin photonic hypercrystal slab serves as a two-dimensional resonator that can be treated accurately as a metasurface. We show that the perfect absorber is equivalent to a metasurface Salisbury screen, where the metasurface formed by the photonic hypercrystal slab provides the appropriate electric sheet conductivity required for critical coupling. We also present examples of combining the perfect absorber with graphene to make optical modulators and to improve the absorption in graphene photodetectors.

  7. Inter-image matching

    NASA Technical Reports Server (NTRS)

    Wolfe, R. H., Jr.; Juday, R. D.

    1982-01-01

    Interimage matching is the process of determining the geometric transformation required to conform spatially one image to another. In principle, the parameters of that transformation are varied until some measure of some difference between the two images is minimized or some measure of sameness (e.g., cross-correlation) is maximized. The number of such parameters to vary is faily large (six for merely an affine transformation), and it is customary to attempt an a priori transformation reducing the complexity of the residual transformation or subdivide the image into small enough match zones (control points or patches) that a simple transformation (e.g., pure translation) is applicable, yet large enough to facilitate matching. In the latter case, a complex mapping function is fit to the results (e.g., translation offsets) in all the patches. The methods reviewed have all chosen one or both of the above options, ranging from a priori along-line correction for line-dependent effects (the high-frequency correction) to a full sensor-to-geobase transformation with subsequent subdivision into a grid of match points.

  8. Is Matching Innate?

    ERIC Educational Resources Information Center

    Gallistel, C. R.; King, Adam Philip; Gottlieb, Daniel; Balci, Fuat; Papachristos, Efstathios B.; Szalecki, Matthew; Carbone, Kimberly S.

    2007-01-01

    Experimentally naive mice matched the proportions of their temporal investments (visit durations) in two feeding hoppers to the proportions of the food income (pellets per unit session time) derived from them in three experiments that varied the coupling between the behavioral investment and food income, from no coupling to strict coupling.…

  9. Derivatives of Matching.

    ERIC Educational Resources Information Center

    Herrnstein, R. J.

    1979-01-01

    The matching law for reinforced behavior solves a differential equation relating infinitesimal changes in behavior to infinitesimal changes in reinforcement. The equation expresses plausible conceptions of behavior and reinforcement, yields a simple nonlinear operator model for acquisition, and suggests a alternative to the economic law of…

  10. Coherent perfect absorption and reflection in slow-light waveguides.

    PubMed

    Gutman, Nadav; Sukhorukov, Andrey A; Chong, Y D; de Sterke, C Martijn

    2013-12-01

    We identify a family of unusual slow-light modes occurring in lossy multimode grating waveguides, for which either the forward or backward mode components, or both, are degenerate. In the fully degenerate case, the response can be modulated between coherent perfect absorption (zero reflection) and perfect reflection by varying the wave amplitudes in a uniform input waveguide. The perfectly absorbed wave has anomalously short absorption length, scaling as the inverse one-third power of the absorptivity.

  11. Will a perfect model agree with perfect observations? The impact of spatial sampling

    NASA Astrophysics Data System (ADS)

    Schutgens, Nick A. J.; Gryspeerdt, Edward; Weigum, Natalie; Tsyro, Svetlana; Goto, Daisuke; Schulz, Michael; Stier, Philip

    2016-05-01

    The spatial resolution of global climate models with interactive aerosol and the observations used to evaluate them is very different. Current models use grid spacings of ˜ 200 km, while satellite observations of aerosol use so-called pixels of ˜ 10 km. Ground site or airborne observations relate to even smaller spatial scales. We study the errors incurred due to different resolutions by aggregating high-resolution simulations (10 km grid spacing) over either the large areas of global model grid boxes ("perfect" model data) or small areas corresponding to the pixels of satellite measurements or the field of view of ground sites ("perfect" observations). Our analysis suggests that instantaneous root-mean-square (RMS) differences of perfect observations from perfect global models can easily amount to 30-160 %, for a range of observables like AOT (aerosol optical thickness), extinction, black carbon mass concentrations, PM2.5, number densities and CCN (cloud condensation nuclei). These differences, due entirely to different spatial sampling of models and observations, are often larger than measurement errors in real observations. Temporal averaging over a month of data reduces these differences more strongly for some observables (e.g. a threefold reduction for AOT), than for others (e.g. a twofold reduction for surface black carbon concentrations), but significant RMS differences remain (10-75 %). Note that this study ignores the issue of temporal sampling of real observations, which is likely to affect our present monthly error estimates. We examine several other strategies (e.g. spatial aggregation of observations, interpolation of model data) for reducing these differences and show their effectiveness. Finally, we examine consequences for the use of flight campaign data in global model evaluation and show that significant biases may be introduced depending on the flight strategy used.

  12. Broadband electrical impedance matching for piezoelectric ultrasound transducers.

    PubMed

    Huang, Haiying; Paramo, Daniel

    2011-12-01

    This paper presents a systematic method for designing broadband electrical impedance matching networks for piezoelectric ultrasound transducers. The design process involves three steps: 1) determine the equivalent circuit of the unmatched piezoelectric transducer based on its measured admittance; 2) design a set of impedance matching networks using a computerized Smith chart; and 3) establish the simulation model of the matched transducer to evaluate the gain and bandwidth of the impedance matching networks. The effectiveness of the presented approach is demonstrated through the design, implementation, and characterization of impedance matching networks for a broadband acoustic emission sensor. The impedance matching network improved the power of the acquired signal by 9 times.

  13. Hypothesis: A perfect day conveys internal time.

    PubMed

    Groß, J V; Fritschi, L; Erren, T C

    2017-04-01

    In 2007 the International Agency for Research on Cancer [IARC] concluded "shift work that involves circadian disruption is probably carcinogenic to humans" (Group 2A). To investigate the "probable" causal link, information on individual chronobiology is needed to specify exposures to circadian disruption associated with shift work. In epidemiological studies this information is usually assessed by questionnaire. The most widely used Morningness-Eveningness-Questionnaire (MEQ) and MunichChronoTypeQuestionnaire (MCTQ) reveal information on circadian type (MEQ) and actual sleep behaviour (MCTQ). As a further option we suggest to obtain preferred sleep times by using what we call the perfect day (PD) approach. We hypothesize that a PD - as a day of completely preferred sleep behaviour - captures pristine internal time. We argue that the PD approach may measure internal time more accurately than the MEQ and MCTQ which convey influences by work and social time pressures. The PD approach may therefore reduce misclassifications of internal time and reveal circadian disruption caused by different shift systems.

  14. Perfect terahertz absorber using fishnet based metafilm

    SciTech Connect

    Azad, Abul Kalam; Shchegolkov, Dmitry Yu; Chen, Houtong; Taylor, Antoinette; Smirnova, E I; O' Hara, John F

    2009-01-01

    We present a perfect terahertz (THz) absorber working for a broad-angle of incidence. The two fold symmetry of rectangular fishnet structure allows either complete absorption or mirror like reflection depending on the polarization of incident the THz beam. Metamaterials enable the ability to control the electromagnetic wave in a unique fashion by designing the permittivity or permeability of composite materials with desired values. Although the initial idea of metamaterials was to obtain a negative index medium, however, the evolution of metamaterials (MMs) offers a variety of practically applicable devices for controlling electromagnetic wave such as tunable filters, modulators, phase shifters, compact antenna, absorbers, etc. Terahertz regime, a crucial domain of the electromagnetic wave, is suffering from the scarcity of the efficient devices and might take the advantage of metamaterials. Here, we demonstrate design, fabrication, and characterization of a terahertz absorber based on a simple fishnet metallic film separated from a ground mirror plane by a dielectric spacer. Such absorbers are in particular important for bolometric terahertz detectors, high sensitivity imaging, and terahertz anechoic chambers. Recently, split-ring-resonators (SRR) have been employed for metamaterial-based absorbers at microwave and THz frequencies. The experimental demonstration reveals that such absorbers have absorptivity close to unity at resonance frequencies. However, the downside of these designs is that they all employ resonators of rather complicated shape with many fine parts and so they are not easy to fabricate and are sensitive to distortions.

  15. Matching current windstorms to historical analogues

    NASA Astrophysics Data System (ADS)

    Becker, Bernd; Maisey, Paul; Scannell, Claire; Vanvyve, Emilie; Mitchell, Lorna; Steptoe, Hamish

    2015-04-01

    assessment of the goodness of fit made by the rank proximity measure. Using this technique a series of potential historical footprints matching the current footprint is found. Each potential match is indexed according to its closeness to the current footprint where an index rating of 0 is a perfect match or "identical twin". Such pattern matching of current and forecast windstorms against an historical archive can enable insurers estimate a rapid prediction of likely loss and aid the timely deployment of staff and funds at the right level.

  16. Resurgence matches quantization

    NASA Astrophysics Data System (ADS)

    Couso-Santamaría, Ricardo; Mariño, Marcos; Schiappa, Ricardo

    2017-04-01

    The quest to find a nonperturbative formulation of topological string theory has recently seen two unrelated developments. On the one hand, via quantization of the mirror curve associated to a toric Calabi–Yau background, it has been possible to give a nonperturbative definition of the topological-string partition function. On the other hand, using techniques of resurgence and transseries, it has been possible to extend the string (asymptotic) perturbative expansion into a transseries involving nonperturbative instanton sectors. Within the specific example of the local {{{P}}2} toric Calabi–Yau threefold, the present work shows how the Borel–Padé–Écalle resummation of this resurgent transseries, alongside occurrence of Stokes phenomenon, matches the string-theoretic partition function obtained via quantization of the mirror curve. This match is highly non-trivial, given the unrelated nature of both nonperturbative frameworks, signaling at the existence of a consistent underlying structure.

  17. Surface matching via currents.

    PubMed

    Vaillant, Marc; Glaunès, Joan

    2005-01-01

    We present a new method for computing an optimal deformation between two arbitrary surfaces embedded in Euclidean 3-dimensional space. Our main contribution is in building a norm on the space of surfaces via representation by currents of geometric measure theory. Currents are an appropriate choice for representations because they inherit natural transformation properties from differential forms. We impose a Hilbert space structure on currents, whose norm gives a convenient and practical way to define a matching functional. Using this Hilbert space norm, we also derive and implement a surface matching algorithm under the large deformation framework, guaranteeing that the optimal solution is a one-to-one regular map of the entire ambient space. We detail an implementation of this algorithm for triangular meshes and present results on 3D face and medical image data.

  18. Electrodynamics analysis on coherent perfect absorber and phase-controlled optical switch.

    PubMed

    Chen, Tianjie; Duan, Shaoguang; Chen, Y C

    2012-05-01

    A coherent perfect absorber is essentially a specially designed Fabry-Perot interferometer, which completely extinguishes the incident coherent light. The one- and two-beam coherent perfect absorbers have been analyzed using classical electrodynamics by considering index matching in layered structures to totally suppress reflections. This approach presents a clear and physically intuitive picture for the principle of operation of a perfect absorber. The results show that the incident beam(s) must have correct phases and amplitudes, and the real and imaginary parts of the refractive indices of the media in the interferometer must satisfy a well-defined relation. Our results are in agreement with those obtained using the S-matrix analysis. However, the results were obtained solely based on the superposition of waves from multiple reflections without invoking the concept of time reversal as does the S-matrix approach. Further analysis shows that the two-beam device can be configured to function as a phase-controlled three-state switch.

  19. A multiband perfect absorber based on hyperbolic metamaterials

    PubMed Central

    Sreekanth, Kandammathe Valiyaveedu; ElKabbash, Mohamed; Alapan, Yunus; Rashed, Alireza R.; Gurkan, Umut A.; Strangi, Giuseppe

    2016-01-01

    In recent years, considerable research efforts have been focused on near-perfect and perfect light absorption using metamaterials spanning frequency ranges from microwaves to visible frequencies. This relatively young field is currently facing many challenges that hampers its possible practical applications. In this paper, we present grating coupled-hyperbolic metamaterials (GC-HMM) as multiband perfect absorber that can offer extremely high flexibility in engineering the properties of electromagnetic absorption. The fabricated GC-HMMs exhibit several highly desirable features for technological applications such as polarization independence, wide angle range, broad- and narrow- band modes, multiband perfect and near perfect absorption in the visible to near-IR and mid-IR spectral range. In addition, we report a direct application of the presented system as an absorption based plasmonic sensor with a record figure of merit for this class of sensors. PMID:27188789

  20. Lattice fluid dynamics from perfect discretizations of continuum flows

    SciTech Connect

    Katz, E.; Wiese, U.

    1998-11-01

    We use renormalization group methods to derive equations of motion for large scale variables in fluid dynamics. The large scale variables are averages of the underlying continuum variables over cubic volumes and naturally exist on a lattice. The resulting lattice dynamics represents a perfect discretization of continuum physics, i.e., grid artifacts are completely eliminated. Perfect equations of motion are derived for static, slow flows of incompressible, viscous fluids. For Hagen-Poiseuille flow in a channel with a square cross section the equations reduce to a perfect discretization of the Poisson equation for the velocity field with Dirichlet boundary conditions. The perfect large scale Poisson equation is used in a numerical simulation and is shown to represent the continuum flow exactly. For nonsquare cross sections one can use a numerical iterative procedure to derive flow equations that are approximately perfect. {copyright} {ital 1998} {ital The American Physical Society}

  1. Implications of cloning for breed improvement strategies: are traditional methods of animal improvement obsolete?

    PubMed

    van Vleck, L D

    1999-01-01

    Can the optimum animal be defined? Will that definition change over time, by location, by market demand? First, assume what may be impossible, that the perfect animal can be defined or that only a limited number of definitions of "perfect" are needed. Then, can the "perfect" animal to match a definition be found? Suppose such an animal is found. Then the question to be answered before trying to clone as a method of genetic improvement becomes "Is the animal perfect because of phenotype or genotype?" In other words, the P = G + E problem exists, which requires traditional methods of genetic evaluation and testing to determine whether genotype (G) or random environmental (E) effects or a combination leads to the apparent perfection in the phenotype (P). For most traits, additive genetic variance accounts for 10 to 50% of total variance, a fraction denoted as heritability. With a simple model, the best prediction of genotypic value is to reduce the apparent phenotypic superiority by multiplying by heritability. Cloning the "perfect" animal also could capture optimum dominance and epistatic genetic effects that are otherwise difficult to select for. For some traits, maternal effects are important. In that case, clones as breeding animals must be "perfect" for both direct and maternal genotypes, or alternatively terminal and maternal clone lines would need to be developed. The use of clones to increase uniformity can be only partially successful. If heritability is 25%, then the standard deviation among clones would be 87% of that of uncloned animals. Only if heritability is 100% will clone mates have complete uniformity. Fixing the genotype could increase susceptibility to failure if environment changes or if the cloned genotype is susceptible to a new disease or if economic conditions change. Cloning, at best, is another tool for animal improvement that joins the list of previous biotechnological inventions, some of which have become cost-effective, such as artificial

  2. Kaizen and ergonomics: the perfect marriage.

    PubMed

    Rodriguez, Martin Antonio; Lopez, Luis Fernando

    2012-01-01

    This paper is an approach of how Kaizen (Continuous Improvement) and Ergonomics could be implemented in the field of work. The Toyota's Team Members are the owners of this job, applying tools and techniques to improve work conditions using the Kaizen Philosophy in a QCC Activity (Quality Control Circle).

  3. Y junctions in photonic crystal channel waveguides: high transmission and impedance matching.

    PubMed

    Boscolo, S; Midrio, M; Krauss, T F

    2002-06-15

    We investigate the efficiency of transmission through photonic crystal Y junctions and show the importance of matching mode symmetries. Furthermore, we show that by adding tuning holes to the input waveguide it is possible to achieve almost perfect impedance matching, leading ideally to unitary transmission through the junction. The model system is based on a triangular photonic lattice of holes in dielectrics to reflect experimental reality.

  4. Digital matched filter ASIC

    NASA Astrophysics Data System (ADS)

    Magill, D. T.; Edwards, G.

    The architecture of a digital matched filter (DMF) and the selected technology used is described. The characteristics of the DMF ASIC are summarized in tabular form. Three architectures are considered for the implementation of a DMF ASIC. First, there is the conventional trapped delay line architecture which requires a large adder tree. The second architecture is the systolic array DMF which consists of a number of identical stages cascaded together. The third architecture is the bank-of-correlators DMF, in which the reference code is recirculated around through the delay line. Since the objective is to maximize the length of the DMF, the tapped delay line architecture is selected. The tapped delay form is designed to support BPSK, QPSK, and OQPSK chip modulation. Matched filter lengths of up to 256 chips can be supported by cascading 4 ASICs. The DMF is designed as a gate array using an advanced double metal, 1.5 micron CMOS process. The regularity of FIR filter architecture allows the core of the device to be laid out very compactly, resulting in efficient usage of the gate array.

  5. Nearly Perfect Fluidity in a High Temperature Superconductor

    DOE PAGES

    Rameau, J. D.; Reber, T. J.; Yang, H. -B.; ...

    2014-10-13

    Perfect fluids are characterized as having the smallest ratio of shear viscosity to entropy density, η/s, consistent with quantum uncertainty and causality. So far, nearly perfect fluids have only been observed in the quark-gluon plasma and in unitary atomic Fermi gases, exotic systems that are amongst the hottest and coldest objects in the known universe, respectively. We use angle resolved photoemission spectroscopy to measure the temperature dependence of an electronic analog of η/s in an optimally doped cuprate high-temperature superconductor, finding it too is a nearly perfect fluid around, and above, its superconducting transition temperature Tc.

  6. Nearly Perfect Fluidity in a High Temperature Superconductor

    SciTech Connect

    Rameau, J. D.; Reber, T. J.; Yang, H. -B.; Akhanjee, S.; Gu, G. D.; Johnson, P. D.; Campbell, S.

    2014-10-13

    Perfect fluids are characterized as having the smallest ratio of shear viscosity to entropy density, η/s, consistent with quantum uncertainty and causality. So far, nearly perfect fluids have only been observed in the quark-gluon plasma and in unitary atomic Fermi gases, exotic systems that are amongst the hottest and coldest objects in the known universe, respectively. We use angle resolved photoemission spectroscopy to measure the temperature dependence of an electronic analog of η/s in an optimally doped cuprate high-temperature superconductor, finding it too is a nearly perfect fluid around, and above, its superconducting transition temperature Tc.

  7. Metamaterial perfect absorber based on artificial dielectric "atoms".

    PubMed

    Liu, Xiaoming; Bi, Ke; Li, Bo; Zhao, Qian; Zhou, Ji

    2016-09-05

    In this work, we numerically designed and then experimentally verified a metamaterial perfect absorber based on artificial dielectric "atoms". This metamaterial absorber is composed of dielectric ceramic material (SrTiO3) "atoms" embedded in a background matrix on a metal plate. The dielectric "atoms" couple strongly to the incident electric and magnetic fields at the Mie resonance mode, leading to the narrow perfect absorption band with simulated and experimental absorptivities of 99% and 98.5% at 8.96 GHz, respectively. The designed metamaterial perfect absorber is polarization insensitive and can operate in wide angle incidence.

  8. The Earliest Matches

    PubMed Central

    Goren-Inbar, Naama; Freikman, Michael; Garfinkel, Yosef; Goring-Morris, Nigel A.; Grosman, Leore

    2012-01-01

    Cylindrical objects made usually of fired clay but sometimes of stone were found at the Yarmukian Pottery Neolithic sites of Sha‘ar HaGolan and Munhata (first half of the 8th millennium BP) in the Jordan Valley. Similar objects have been reported from other Near Eastern Pottery Neolithic sites. Most scholars have interpreted them as cultic objects in the shape of phalli, while others have referred to them in more general terms as “clay pestles,” “clay rods,” and “cylindrical clay objects.” Re-examination of these artifacts leads us to present a new interpretation of their function and to suggest a reconstruction of their technology and mode of use. We suggest that these objects were components of fire drills and consider them the earliest evidence of a complex technology of fire ignition, which incorporates the cylindrical objects in the role of matches. PMID:22870306

  9. The earliest matches.

    PubMed

    Goren-Inbar, Naama; Freikman, Michael; Garfinkel, Yosef; Goring-Morris, A Nigel; Goring-Morris, Nigel A; Grosman, Leore

    2012-01-01

    Cylindrical objects made usually of fired clay but sometimes of stone were found at the Yarmukian Pottery Neolithic sites of Sha'ar HaGolan and Munhata (first half of the 8(th) millennium BP) in the Jordan Valley. Similar objects have been reported from other Near Eastern Pottery Neolithic sites. Most scholars have interpreted them as cultic objects in the shape of phalli, while others have referred to them in more general terms as "clay pestles," "clay rods," and "cylindrical clay objects." Re-examination of these artifacts leads us to present a new interpretation of their function and to suggest a reconstruction of their technology and mode of use. We suggest that these objects were components of fire drills and consider them the earliest evidence of a complex technology of fire ignition, which incorporates the cylindrical objects in the role of matches.

  10. Distinctiveness Maps for Image Matching

    NASA Technical Reports Server (NTRS)

    Manduchi, Roberto; Tomasi, Carlo

    2000-01-01

    Stereo correspondence is hard because different image features can look alike. We propose a measure for the ambiguity of image points that allows matching distinctive points first and breaks down the matching task into smaller and separate subproblems. Experiments with an algorithm based on this measure demonstrate the ensuing efficiency and low likelihood of incorrect matches.

  11. Infrared Perfect Ultra-narrow Band Absorber as Plasmonic Sensor

    NASA Astrophysics Data System (ADS)

    Wu, Dong; Liu, Yumin; Li, Ruifang; Chen, Lei; Ma, Rui; Liu, Chang; Ye, Han

    2016-11-01

    We propose and numerically investigate a novel perfect ultra-narrow band absorber based on a metal-dielectric-metal-dielectric-metal periodic structure working at near-infrared region, which consists of a dielectric layer sandwiched by a metallic nanobar array and a thin gold film over a dielectric layer supported by a metallic film. The absorption efficiency and ultra-narrow band of the absorber are about 98 % and 0.5 nm, respectively. The high absorption is contributed to localized surface plasmon resonance, which can be influenced by the structure parameters and the refractive index of dielectric layer. Importantly, the ultra-narrow band absorber shows an excellent sensing performance with a high sensitivity of 2400 nm/RIU and an ultra-high figure of merit of 4800. The FOM of refractive index sensor is significantly improved, compared with any previously reported plasmonic sensor. The influences of structure parameters on the sensing performance are also investigated, which will have a great guiding role to design high-performance refractive index sensors. The designed structure has huge potential in sensing application.

  12. High performance projectile seal development for non perfect railgun bores

    SciTech Connect

    Wolfe, T.R.; Vine, F.E. Le; Riedy, P.E.; Panlasigui, A.; Hawke, R.S.; Susoeff, A.R.

    1997-01-01

    The sealing of high pressure gas behind an accelerating projectile has been developed over centuries of use in conventional guns and cannons. The principal concern was propulsion efficiency and trajectory accuracy and repeatability. The development of guns for use as high pressure equation-of-state (EOS) research tools, increased the importance of better seals to prevent gas leakage from interfering with the experimental targets. The development of plasma driven railguns has further increased the need for higher quality seals to prevent gas and plasma blow-by. This paper summarizes more than a decade of effort to meet these increased requirements. In small bore railguns, the first improvement was prompted by the need to contain the propulsive plasma behind the projectile to avoid the initiation of current conducting paths in front of the projectile. The second major requirements arose from the development of a railgun to serve as an EOS tool where it was necessary to maintain an evacuated region in front of the projectile throughout the acceleration process. More recently, the techniques developed for the small bore guns have been applied to large bore railguns and electro-thermal chemical guns in order to maximize their propulsion efficiency. Furthermore, large bore railguns are often less rigid and less straight than conventional homogeneous material guns. Hence, techniques to maintain seals in non perfect, non homogeneous material launchers have been developed and are included in this paper.

  13. New exact perfect fluid solutions of Einstein's equations. II

    NASA Astrophysics Data System (ADS)

    Uggla, Claes; Rosquist, Kjell

    1990-12-01

    A family of new spatially homogeneous Bianchi type VIh perfect fluid solutions of the Einstein equations is presented. The fluid flow is orthogonal to the spatially homogeneous hypersurfaces, and the pressure is proportional to the energy density.

  14. Perfection and the Bomb: Nuclear Weapons, Teleology, and Motives.

    ERIC Educational Resources Information Center

    Brummett, Barry

    1989-01-01

    Uses Kenneth Burke's theory of perfection to explore the vocabularies of nuclear weapons in United States public discourse and how "the Bomb" as a God term has gained imbalanced ascendancy in centers of power. (MS)

  15. Perfect Actions ---From the Theoretical Background to Recent Developments ---

    NASA Astrophysics Data System (ADS)

    Hasenfratz, P.

    This lecture note starts with a pedagogical introduction to the theoretical background and properties of perfect actions and ends with a discussion on the recent developments concerning chiral symmetry.

  16. Dynamics of microparticles trapped in a perfect vortex beam.

    PubMed

    Chen, Mingzhou; Mazilu, Michael; Arita, Yoshihiko; Wright, Ewan M; Dholakia, Kishan

    2013-11-15

    We analyze microparticle dynamics within a "perfect" vortex beam. In contrast to other vortex fields, for any given integer value of the topological charge, a "perfect" vortex beam has the same annular intensity profile with fixed radius of peak intensity. For a given topological charge, the field possesses a well-defined orbital angular momentum density at each point in space, invariant with respect to azimuthal position. We experimentally create a perfect vortex and correct the field in situ, to trap and set in motion trapped microscopic particles. For a given topological charge, a single trapped particle exhibits the same local angular velocity moving in such a field independent of its azimuthal position. We also investigate particle dynamics in "perfect" vortex beams of fractional topological charge. This light field may be applied for novel studies in optical trapping of particles, atoms, and quantum gases.

  17. Senseless demolition in progress, showing destruction of perfectly decent and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Senseless demolition in progress, showing destruction of perfectly decent and recyclable mill building. Problem exacerbated by high value of scrap iron. - Phoenix Iron Company, Rolling Mill, North of French Creek, west of Fairview Avenue, Phoenixville, Chester County, PA

  18. Synthesis of CoFe/Al2O3 composite nanoparticles as the impedance matching layer of wideband multilayer absorber

    NASA Astrophysics Data System (ADS)

    Zhen, L.; Gong, Y. X.; Jiang, J. T.; Xu, C. Y.; Shao, W. Z.; Liu, P.; Tang, J.

    2011-04-01

    CoFe/Al2O3 composite nanoparticles were successfully prepared by hydrogen-thermally reducing cobalt aluminum ferrite. Compared with CoFe alloy nanoparticles, the permeability of CoFe/Al2O3 composite nanoparticles was remarkably enhanced and an improved impedance characteristic was achieved due to the introduction of insulated Al2O3. A multilayer absorber with CoFe/Al2O3 composite nanoparticles as the impedance matching layer and CoFe nanoflake as the dissipation layer was designed by using genetic algorithm, in which an ultrawide operation frequency bandwidth over 2.5-18 GHz was obtained. The microwave absorption performance in both normal and oblique incident case was evaluated by using electromagnetic simulator. The backward radar cross-section (RCS) was decreased at least 10 dB over a wide frequency range by covering the multilayer absorber on the surface of perfect electrical conductive plate.

  19. Constraint-based stereo matching

    NASA Technical Reports Server (NTRS)

    Kuan, D. T.

    1987-01-01

    The major difficulty in stereo vision is the correspondence problem that requires matching features in two stereo images. Researchers describe a constraint-based stereo matching technique using local geometric constraints among edge segments to limit the search space and to resolve matching ambiguity. Edge segments are used as image features for stereo matching. Epipolar constraint and individual edge properties are used to determine possible initial matches between edge segments in a stereo image pair. Local edge geometric attributes such as continuity, junction structure, and edge neighborhood relations are used as constraints to guide the stereo matching process. The result is a locally consistent set of edge segment correspondences between stereo images. These locally consistent matches are used to generate higher-level hypotheses on extended edge segments and junctions to form more global contexts to achieve global consistency.

  20. Perfecting patient flow in the surgical setting.

    PubMed

    Amato-Vealey, Elaine J; Fountain, Patricia; Coppola, Deborah

    2012-07-01

    Reduced surgical efficiency and productivity, delayed patient discharges, and prolonged use of hospital resources are the results of an OR that is unable to move patients to the postanesthesia care unit or other patient units. A primary reason for perioperative patient flow delay is the lack of hospital beds to accommodate surgical patients, which consequently causes backups of patients currently in the surgical suite. In one facility, implementing Six Sigma methodology helped to improve OR patient flow by identifying ways that frontline staff members could work more intelligently and more efficiently, and with less stress to streamline workflow and eliminate redundancy and waste in ways that did not necessitate reducing the number of employees. The results were improved employee morale, job satisfaction and safety, and an enhanced patient experience.

  1. Accuracy and robustness evaluation in stereo matching

    NASA Astrophysics Data System (ADS)

    Nguyen, Duc M.; Hanca, Jan; Lu, Shao-Ping; Schelkens, Peter; Munteanu, Adrian

    2016-09-01

    Stereo matching has received a lot of attention from the computer vision community, thanks to its wide range of applications. Despite of the large variety of algorithms that have been proposed so far, it is not trivial to select suitable algorithms for the construction of practical systems. One of the main problems is that many algorithms lack sufficient robustness when employed in various operational conditions. This problem is due to the fact that most of the proposed methods in the literature are usually tested and tuned to perform well on one specific dataset. To alleviate this problem, an extensive evaluation in terms of accuracy and robustness of state-of-the-art stereo matching algorithms is presented. Three datasets (Middlebury, KITTI, and MPEG FTV) representing different operational conditions are employed. Based on the analysis, improvements over existing algorithms have been proposed. The experimental results show that our improved versions of cross-based and cost volume filtering algorithms outperform the original versions with large margins on Middlebury and KITTI datasets. In addition, the latter of the two proposed algorithms ranks itself among the best local stereo matching approaches on the KITTI benchmark. Under evaluations using specific settings for depth-image-based-rendering applications, our improved belief propagation algorithm is less complex than MPEG's FTV depth estimation reference software (DERS), while yielding similar depth estimation performance. Finally, several conclusions on stereo matching algorithms are also presented.

  2. Matching roots to their environment

    PubMed Central

    White, Philip J.; George, Timothy S.; Gregory, Peter J.; Bengough, A. Glyn; Hallett, Paul D.; McKenzie, Blair M.

    2013-01-01

    Background Plants form the base of the terrestrial food chain and provide medicines, fuel, fibre and industrial materials to humans. Vascular land plants rely on their roots to acquire the water and mineral elements necessary for their survival in nature or their yield and nutritional quality in agriculture. Major biogeochemical fluxes of all elements occur through plant roots, and the roots of agricultural crops have a significant role to play in soil sustainability, carbon sequestration, reducing emissions of greenhouse gasses, and in preventing the eutrophication of water bodies associated with the application of mineral fertilizers. Scope This article provides the context for a Special Issue of Annals of Botany on ‘Matching Roots to Their Environment’. It first examines how land plants and their roots evolved, describes how the ecology of roots and their rhizospheres contributes to the acquisition of soil resources, and discusses the influence of plant roots on biogeochemical cycles. It then describes the role of roots in overcoming the constraints to crop production imposed by hostile or infertile soils, illustrates root phenotypes that improve the acquisition of mineral elements and water, and discusses high-throughput methods to screen for these traits in the laboratory, glasshouse and field. Finally, it considers whether knowledge of adaptations improving the acquisition of resources in natural environments can be used to develop root systems for sustainable agriculture in the future. PMID:23821619

  3. Lattice-Matched Semiconductor Layers on Single Crystalline Sapphire Substrate

    NASA Technical Reports Server (NTRS)

    Choi, Sang; King, Glen; Park, Yeonjoon

    2009-01-01

    SiGe is an important semiconductor alloy for high-speed field effect transistors (FETs), high-temperature thermoelectric devices, photovoltaic solar cells, and photon detectors. The growth of SiGe layer is difficult because SiGe alloys have different lattice constants from those of the common Si wafers, which leads to a high density of defects, including dislocations, micro-twins, cracks, and delaminations. This innovation utilizes newly developed rhombohedral epitaxy of cubic semiconductors on trigonal substrates in order to solve the lattice mismatch problem of SiGe by using trigonal single crystals like sapphire (Al2O3) as substrate to give a unique growth-orientation to the SiGe layer, which is automatically controlled at the interface upon sapphire (0001). This technology is different from previous silicon on insulator (SOI) or SGOI (SiGe on insulator) technologies that use amorphous SiO2 as the growth plane. A cubic semiconductor crystal is a special case of a rhombohedron with the inter-planar angle, alpha = 90 deg. With a mathematical transformation, all rhombohedrons can be described by trigonal crystal lattice structures. Therefore, all cubic lattice constants and crystal planes (hkl) s can be transformed into those of trigonal crystal parameters. These unique alignments enable a new opportunity of perfect lattice matching conditions, which can eliminate misfit dislocations. Previously, these atomic alignments were thought to be impossible or very difficult. With the invention of a new x-ray diffraction measurement method here, growth of cubic semiconductors on trigonal crystals became possible. This epitaxy and lattice-matching condition can be applied not only to SiGe (111)/sapphire (0001) substrate relations, but also to other crystal structures and other materials, including similar crystal structures which have pointgroup rotational symmetries by 120 because the cubic (111) direction has 120 rotational symmetry. The use of slightly miscut (less than

  4. Computer-Generated Holographic Matched Filters

    NASA Astrophysics Data System (ADS)

    Butler, Steven Frank

    This dissertation presents techniques for the use of computer-generated holograms (CGH) for matched filtering. An overview of the supporting technology is provided. Included are techniques for modifying existing CGH algorithms to serve as matched filters in an optical correlator. It shows that matched filters produced in this fashion can be modified to improve the signal-to-noise and efficiency over that possible with conventional holography. The effect and performance of these modifications are demonstrated. In addition, a correction of film non-linearity in continuous -tone filter production is developed. Computer simulations provide quantitative and qualitative demonstration of theoretical principles, with specific examples validated in optical hardware. Conventional and synthetic holograms, both bleached and unbleached, are compared.

  5. Matched filter based iterative adaptive approach

    NASA Astrophysics Data System (ADS)

    Nepal, Ramesh; Zhang, Yan Rockee; Li, Zhengzheng; Blake, William

    2016-05-01

    Matched Filter sidelobes from diversified LPI waveform design and sensor resolution are two important considerations in radars and active sensors in general. Matched Filter sidelobes can potentially mask weaker targets, and low sensor resolution not only causes a high margin of error but also limits sensing in target-rich environment/ sector. The improvement in those factors, in part, concern with the transmitted waveform and consequently pulse compression techniques. An adaptive pulse compression algorithm is hence desired that can mitigate the aforementioned limitations. A new Matched Filter based Iterative Adaptive Approach, MF-IAA, as an extension to traditional Iterative Adaptive Approach, IAA, has been developed. MF-IAA takes its input as the Matched Filter output. The motivation here is to facilitate implementation of Iterative Adaptive Approach without disrupting the processing chain of traditional Matched Filter. Similar to IAA, MF-IAA is a user parameter free, iterative, weighted least square based spectral identification algorithm. This work focuses on the implementation of MF-IAA. The feasibility of MF-IAA is studied using a realistic airborne radar simulator as well as actual measured airborne radar data. The performance of MF-IAA is measured with different test waveforms, and different Signal-to-Noise (SNR) levels. In addition, Range-Doppler super-resolution using MF-IAA is investigated. Sidelobe reduction as well as super-resolution enhancement is validated. The robustness of MF-IAA with respect to different LPI waveforms and SNR levels is also demonstrated.

  6. Complexity matching in dyadic conversation.

    PubMed

    Abney, Drew H; Paxton, Alexandra; Dale, Rick; Kello, Christopher T

    2014-12-01

    Recent studies of dyadic interaction have examined phenomena of synchronization, entrainment, alignment, and convergence. All these forms of behavioral matching have been hypothesized to play a supportive role in establishing coordination and common ground between interlocutors. In the present study, evidence is found for a new kind of coordination termed complexity matching. Temporal dynamics in conversational speech signals were analyzed through time series of acoustic onset events. Timing in periods of acoustic energy was found to exhibit behavioral matching that reflects complementary timing in turn-taking. In addition, acoustic onset times were found to exhibit power law clustering across a range of timescales, and these power law functions were found to exhibit complexity matching that is distinct from behavioral matching. Complexity matching is discussed in terms of interactive alignment and other theoretical principles that lead to new hypotheses about information exchange in dyadic conversation and interaction in general.

  7. Class of near-perfect coded apertures

    NASA Technical Reports Server (NTRS)

    Cannon, T. M.; Fenimore, E. E.

    1977-01-01

    Coded aperture imaging of gamma ray sources has long promised an improvement in the sensitivity of various detector systems. The promise has remained largely unfulfilled, however, for either one of two reasons. First, the encoding/decoding method produces artifacts, which even in the absence of quantum noise, restrict the quality of the reconstructed image. This is true of most correlation-type methods. Second, if the decoding procedure is of the deconvolution variety, small terms in the transfer function of the aperture can lead to excessive noise in the reconstructed image. It is proposed to circumvent both of these problems by use of a uniformly redundant array (URA) as the coded aperture in conjunction with a special correlation decoding method.

  8. Structural color printing based on plasmonic metasurfaces of perfect light absorption

    SciTech Connect

    Cheng, Fei; Gao, Jie; Luk, Ting S.; Yang, Xiaodong

    2015-06-05

    Subwavelength structural color filtering and printing technologies employing plasmonic nanostructures have recently been recognized as an important and beneficial complement to the traditional colorant-based pigmentation. However, the color saturation, brightness and incident angle tolerance of structural color printing need to be improved to meet the application requirement. Here we demonstrate a structural color printing method based on plasmonic metasurfaces of perfect light absorption to improve color performances such as saturation and brightness. Thin-layer perfect absorbers with periodic hole arrays are designed at visible frequencies and the absorption peaks are tuned by simply adjusting the hole size and periodicity. Near perfect light absorption with high quality factors are obtained to realize high-resolution, angle-insensitive plasmonic color printing with high color saturation and brightness. Moreover, the fabricated metasurfaces can be protected with a protective coating for ambient use without degrading performances. The demonstrated structural color printing platform offers great potential for applications ranging from security marking to information storage.

  9. Structural color printing based on plasmonic metasurfaces of perfect light absorption

    PubMed Central

    Cheng, Fei; Gao, Jie; Luk, Ting S.; Yang, Xiaodong

    2015-01-01

    Subwavelength structural color filtering and printing technologies employing plasmonic nanostructures have recently been recognized as an important and beneficial complement to the traditional colorant-based pigmentation. However, the color saturation, brightness and incident angle tolerance of structural color printing need to be improved to meet the application requirement. Here we demonstrate a structural color printing method based on plasmonic metasurfaces of perfect light absorption to improve color performances such as saturation and brightness. Thin-layer perfect absorbers with periodic hole arrays are designed at visible frequencies and the absorption peaks are tuned by simply adjusting the hole size and periodicity. Near perfect light absorption with high quality factors are obtained to realize high-resolution, angle-insensitive plasmonic color printing with high color saturation and brightness. Moreover, the fabricated metasurfaces can be protected with a protective coating for ambient use without degrading performances. The demonstrated structural color printing platform offers great potential for applications ranging from security marking to information storage. PMID:26047486

  10. Structural color printing based on plasmonic metasurfaces of perfect light absorption.

    PubMed

    Cheng, Fei; Gao, Jie; Luk, Ting S; Yang, Xiaodong

    2015-06-05

    Subwavelength structural color filtering and printing technologies employing plasmonic nanostructures have recently been recognized as an important and beneficial complement to the traditional colorant-based pigmentation. However, the color saturation, brightness and incident angle tolerance of structural color printing need to be improved to meet the application requirement. Here we demonstrate a structural color printing method based on plasmonic metasurfaces of perfect light absorption to improve color performances such as saturation and brightness. Thin-layer perfect absorbers with periodic hole arrays are designed at visible frequencies and the absorption peaks are tuned by simply adjusting the hole size and periodicity. Near perfect light absorption with high quality factors are obtained to realize high-resolution, angle-insensitive plasmonic color printing with high color saturation and brightness. Moreover, the fabricated metasurfaces can be protected with a protective coating for ambient use without degrading performances. The demonstrated structural color printing platform offers great potential for applications ranging from security marking to information storage.

  11. Structural color printing based on plasmonic metasurfaces of perfect light absorption

    NASA Astrophysics Data System (ADS)

    Cheng, Fei; Gao, Jie; Luk, Ting S.; Yang, Xiaodong

    2015-06-01

    Subwavelength structural color filtering and printing technologies employing plasmonic nanostructures have recently been recognized as an important and beneficial complement to the traditional colorant-based pigmentation. However, the color saturation, brightness and incident angle tolerance of structural color printing need to be improved to meet the application requirement. Here we demonstrate a structural color printing method based on plasmonic metasurfaces of perfect light absorption to improve color performances such as saturation and brightness. Thin-layer perfect absorbers with periodic hole arrays are designed at visible frequencies and the absorption peaks are tuned by simply adjusting the hole size and periodicity. Near perfect light absorption with high quality factors are obtained to realize high-resolution, angle-insensitive plasmonic color printing with high color saturation and brightness. Moreover, the fabricated metasurfaces can be protected with a protective coating for ambient use without degrading performances. The demonstrated structural color printing platform offers great potential for applications ranging from security marking to information storage.

  12. Biomechanics and biocompatibility of the perfect conduit—can we build one?

    PubMed Central

    Ng, Martin K.C.; Bannon, Paul G.

    2013-01-01

    No currently available conduit meets the criteria for an ideal coronary artery bypass graft. The perfect conduit would combine the availability and complication-free harvest of a synthetic vessel with the long-term patency performance of the internal mammary artery. However, current polymer conduits suffer from inelastic mechanical properties and especially poor surface biocompatibility, resulting in early loss of patency as a coronary graft. Approaches to manufacture an improved conduit using new polymers or polymer surfaces, acellular matrices, or cellular constructs have to date failed to achieve a commercially successful alternative. Elastin, by mimicking the native extracellular environment as well as providing elasticity, provides the ‘missing link’ in vascular conduit design and brings new hope for realization of the perfect conduit. PMID:23977620

  13. Almost perfect sequences applied for ionospheric oblique backscattering detection

    NASA Astrophysics Data System (ADS)

    Chen, Gang; Zhao, Zhengyu; Pu, Tianyao; Huang, Yujie; Zhu, Guoqiang

    2009-10-01

    Pseudorandom sequences are often used in radio systems; however, the nonzero out-of-phase autocorrelation of many binary sequences induces range sidelobes which significantly reduce the echo signal-to-noise ratio (SNR). In this paper, the use of almost perfect sequences, exhibiting zero out-of-phase autocorrelation except one value in the middle is examined with reference to common m sequences and perfect sequence. The ambiguity functions demonstrate that it is possible to use the almost perfect sequences for ranging without sidelobes and that their Doppler measurement performance is similar to m sequence of the same length. This is an important result for ionospheric oblique backscattering detection where the echoes are superposed and where range sidelobes can submerge the main lobes of weak signals. The 124-bit almost perfect sequence and the 127-bit m sequence are applied to the Wuhan Ionospheric Oblique Backscattering Sounding System for sequence testing. The test results have proven that the almost perfect sequence exhibits a higher echo SNR for the same detection conditions.

  14. Interference control of perfect photon absorption in cavity quantum electrodynamics

    NASA Astrophysics Data System (ADS)

    Wang, Liyong; Di, Ke; Zhu, Yifu; Agarwal, G. S.

    2017-01-01

    We propose and analyze a scheme for controlling coherent photon transmission and reflection in a cavity-quantum-electrodynamics (CQED) system consisting of an optical resonator coupled with three-level atoms coherently prepared by a control laser from free space. When the control laser is off and the cavity is excited by two identical light fields from two ends of the cavity, the two input light fields can be completely absorbed by the CQED system and the light energy is converted into the excitation of the polariton states, but no light can escape from the cavity. Two distinct cases of controlling the perfect photon absorption are analyzed: (a) when the control laser is tuned to the atomic resonance and creates electromagnetically induced transparency, the perfect photon absorption is suppressed and the input light fields are nearly completely transmitted through the cavity; (b) when the control laser is tuned to the polariton state resonance and inhibits the polariton state excitation, the perfect photon absorption is again suppressed and the input light fields are nearly completely reflected from the cavity. Thus, the CQED system can act as a perfect absorber or near-perfect transmitter and/or reflector by simply turning the control laser off or on. Such interference control of the coherent photon-atom interaction in the CQED system should be useful for a variety of applications in optical logical devices.

  15. Line segment matching and reconstruction via exploiting coplanar cues

    NASA Astrophysics Data System (ADS)

    Li, Kai; Yao, Jian

    2017-03-01

    This paper introduces a new system for reconstructing 3D scenes from Line Segments (LS) on images. A new LS matching algorithm and a novel 3D LS reconstruction algorithm are incorporated into the system. Two coplanar cues that indicates image LSs are coplanar in physical (3D) space are extensively exploited in both algorithms: (1) adjacent image LSs are coplanar in space in a high possibility; (2) the projections of coplanar 3D LSs in two images are related by the same planar homography. Based on these two cues, we efficiently match LSs from two images firstly in pairs through matching the V-junctions formed by adjacent LSs, and secondly in individuals by exploiting local homographies. We extract for each V-junction a scale and affine invariant local region to match V-junctions from two images. The local homographies estimated from V-junction matches are used to match LSs in individuals. To get 3D LSs from the obtained LS matches, we propose to first estimate space planes from clustered LS matches and then back-project image LSs onto the space planes. Markov Random Field (MRF) is introduced to help more reliable LS match clustering. Experiments shows our LS matching algorithm significantly improves the efficiency of state-of-the-art methods while achieves comparable matching performance, and our 3D LS reconstruction algorithm generates more complete and detailed 3D scene models using much fewer images.

  16. Spectrally matched upconverting luminescent nanoparticles for monitoring enzymatic reactions.

    PubMed

    Wilhelm, Stefan; del Barrio, Melisa; Heiland, Josef; Himmelstoß, Sandy F; Galbán, Javier; Wolfbeis, Otto S; Hirsch, Thomas

    2014-09-10

    We report on upconverting luminescent nanoparticles (UCLNPs) that are spectrally tuned such that their emission matches the absorption bands of the two most important species associated with enzymatic redox reactions. The core-shell UCLNPs consist of a β-NaYF4 core doped with Yb(3+)/Tm(3+) ions and a shell of pure β-NaYF4. Upon 980 nm excitation, they display emission bands peaking at 360 and 475 nm, which is a perfect match to the absorption bands of the enzyme cosubstrate NADH and the coenzyme FAD, respectively. By exploiting these spectral overlaps, we have designed fluorescent detection schemes for NADH and FAD that are based on the modulation of the emission intensities of UCLNPs by FAD and NADH via an inner filter effect.

  17. Tunable graphene-based mid-infrared plasmonic wide-angle narrowband perfect absorber

    PubMed Central

    Li, Hongju; Wang, Lingling; Zhai, Xiang

    2016-01-01

    In this paper, the periodic double-layer graphene ribbon arrays placed near a metallic ground plate coated by a dielectric layer are proposed and analyzed by the coupled-mode theory (CMT) to predict the perfect absorption response in the mid-infrared region. Numerical simulations of the finite-difference time-domain (FDTD) method confirm this effect and give the underlying physical origin. The anti-symmetric dipole-dipole coupling mode is supported by the double-layer graphene ribbons and acts as the electrical resonance to suppress the reflection, because of the impedance matching. The transmission from this system is restricted by the ultra-thick metallic ground plate. All incident electromagnetic energy is efficiently confined in the interlayer between graphene ribbons and the metallic plate, and the dramatic narrowband perfect absorption peak with the FWHM (full width at half maximums) of 300 nm hence is achieved. The spectral position of the absorption peak can be dynamically tuned by a small change in the chemical potential of graphene, in addition to varying geometrical parameters of the absorber. Meanwhile, this device exhibits good absorption stability over a wide angle range of incidence around ± 60° at least. Such absorber will benefit the fabrication of mid-infrared nano-photonic devices for optical filtering and storage. PMID:27845350

  18. Tunable graphene-based mid-infrared plasmonic wide-angle narrowband perfect absorber

    NASA Astrophysics Data System (ADS)

    Li, Hongju; Wang, Lingling; Zhai, Xiang

    2016-11-01

    In this paper, the periodic double-layer graphene ribbon arrays placed near a metallic ground plate coated by a dielectric layer are proposed and analyzed by the coupled-mode theory (CMT) to predict the perfect absorption response in the mid-infrared region. Numerical simulations of the finite-difference time-domain (FDTD) method confirm this effect and give the underlying physical origin. The anti-symmetric dipole-dipole coupling mode is supported by the double-layer graphene ribbons and acts as the electrical resonance to suppress the reflection, because of the impedance matching. The transmission from this system is restricted by the ultra-thick metallic ground plate. All incident electromagnetic energy is efficiently confined in the interlayer between graphene ribbons and the metallic plate, and the dramatic narrowband perfect absorption peak with the FWHM (full width at half maximums) of 300 nm hence is achieved. The spectral position of the absorption peak can be dynamically tuned by a small change in the chemical potential of graphene, in addition to varying geometrical parameters of the absorber. Meanwhile, this device exhibits good absorption stability over a wide angle range of incidence around ± 60° at least. Such absorber will benefit the fabrication of mid-infrared nano-photonic devices for optical filtering and storage.

  19. Large-Scale All-Dielectric Metamaterial Perfect Reflectors

    SciTech Connect

    Moitra, Parikshit; Slovick, Brian A.; li, Wei; Kravchencko, Ivan I.; Briggs, Dayrl P.; Krishnamurthy, S.; Valentine, Jason

    2015-05-08

    All-dielectric metamaterials offer a potential low-loss alternative to plasmonic metamaterials at optical frequencies. In this paper, we take advantage of the low absorption loss as well as the simple unit cell geometry to demonstrate large-scale (centimeter-sized) all-dielectric metamaterial perfect reflectors made from silicon cylinder resonators. These perfect reflectors, operating in the telecommunications band, were fabricated using self-assembly based nanosphere lithography. In spite of the disorder originating from the self-assembly process, the average reflectance of the metamaterial perfect reflectors is 99.7% at 1530 nm, surpassing the reflectance of metallic mirrors. Moreover, the spectral separation of the electric and magnetic resonances can be chosen to achieve the required reflection bandwidth while maintaining a high tolerance to disorder. Finally, the scalability of this design could lead to new avenues of manipulating light for low-loss and large-area photonic applications.

  20. Experimental perfect state transfer of an entangled photonic qubit

    PubMed Central

    Chapman, Robert J.; Santandrea, Matteo; Huang, Zixin; Corrielli, Giacomo; Crespi, Andrea; Yung, Man-Hong; Osellame, Roberto; Peruzzo, Alberto

    2016-01-01

    The transfer of data is a fundamental task in information systems. Microprocessors contain dedicated data buses that transmit bits across different locations and implement sophisticated routing protocols. Transferring quantum information with high fidelity is a challenging task, due to the intrinsic fragility of quantum states. Here we report on the implementation of the perfect state transfer protocol applied to a photonic qubit entangled with another qubit at a different location. On a single device we perform three routing procedures on entangled states, preserving the encoded quantum state with an average fidelity of 97.1%, measuring in the coincidence basis. Our protocol extends the regular perfect state transfer by maintaining quantum information encoded in the polarization state of the photonic qubit. Our results demonstrate the key principle of perfect state transfer, opening a route towards data transfer for quantum computing systems. PMID:27088483

  1. Large-Scale All-Dielectric Metamaterial Perfect Reflectors

    DOE PAGES

    Moitra, Parikshit; Slovick, Brian A.; li, Wei; ...

    2015-05-08

    All-dielectric metamaterials offer a potential low-loss alternative to plasmonic metamaterials at optical frequencies. In this paper, we take advantage of the low absorption loss as well as the simple unit cell geometry to demonstrate large-scale (centimeter-sized) all-dielectric metamaterial perfect reflectors made from silicon cylinder resonators. These perfect reflectors, operating in the telecommunications band, were fabricated using self-assembly based nanosphere lithography. In spite of the disorder originating from the self-assembly process, the average reflectance of the metamaterial perfect reflectors is 99.7% at 1530 nm, surpassing the reflectance of metallic mirrors. Moreover, the spectral separation of the electric and magnetic resonances canmore » be chosen to achieve the required reflection bandwidth while maintaining a high tolerance to disorder. Finally, the scalability of this design could lead to new avenues of manipulating light for low-loss and large-area photonic applications.« less

  2. INFOODS guidelines for food matching

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is necessary to match food consumption data with food composition data in order to calculate estimates of nutrient intakes and dietary exposure. This can be done manually or through an automated system. As food matching procedures are key to obtaining high quality estimations of nutrient intake...

  3. Drawing Trees with Perfect Angular Resolution and Polynomial Area

    DTIC Science & Technology

    2010-01-01

    ized. Fig. 7: Placing a single disk D′ in the ex- tended small zone of Di (shaded gray). C2 C3 C4 C5 C6 C7 v1 v2 v4 v3 v5 v6 v7 Fig. 8: Drawing a heavy...behavior when required to have perfect angular resolution. This tree has as its spine a k-vertex path, each vertex of which has 3 additional leaf nodes...embedded on the same side of the spine . When drawn with straight-line edges, no crossings, and with perfect angular resolution, the caterpillar is forced

  4. Computational issues for perfect simulation in spatial point patterns

    NASA Astrophysics Data System (ADS)

    Mateu, Jorge; Artés, Jordi; López, José A.

    2004-04-01

    Due to model complexity, spatial statistics often relies on simulation methods. Probably the most common such method is Markov chain Monte Carlo (MCMC) which draws approximate samples of the target distribution as the equilibrium distribution of a Markov chain. Perfect simulation methods are MCMC algorithms which ensure that the exact target distribution is sampled. This paper describes perfect simulation methods of locally stable point processes based on coupling from the past algorithms and provides an intensive simulation study analyzing the behaviour of these techniques under a large variety of practical situations.

  5. Dual band metamaterial perfect absorber based on artificial dielectric "molecules".

    PubMed

    Liu, Xiaoming; Lan, Chuwen; Li, Bo; Zhao, Qian; Zhou, Ji

    2016-07-13

    Dual band metamaterial perfect absorbers with two absorption bands are highly desirable because of their potential application areas such as detectors, transceiver system, and spectroscopic imagers. However, most of these dual band metamaterial absorbers proposed were based on resonances of metal patterns. Here, we numerically and experimentally demonstrate a dual band metamaterial perfect absorber composed of artificial dielectric "molecules" with high symmetry. The artificial dielectric "molecule" consists of four "atoms" of two different sizes corresponding to two absorption bands with near unity absorptivity. Numerical and experimental absorptivity verify that the dual-band metamaterial absorber is polarization insensitive and can operate in wide-angle incidence.

  6. Dual band metamaterial perfect absorber based on Mie resonances

    NASA Astrophysics Data System (ADS)

    Liu, Xiaoming; Lan, Chuwen; Bi, Ke; Li, Bo; Zhao, Qian; Zhou, Ji

    2016-08-01

    We numerically and experimentally demonstrated a polarization insensitive dual-band metamaterial perfect absorber working in wide incident angles based on the two magnetic Mie resonances of a single dielectric "atom" with simple structure. Two absorption bands with simulated absorptivity of 99% and 96%, experimental absorptivity of 97% and 94% at 8.45 and 11.97 GHz were achieved due to the simultaneous magnetic and electric resonances in dielectric "atom" and copper plate. Mie resonances of dielectric "atom" provide a simple way to design metamaterial perfect absorbers with high symmetry.

  7. Clebsch Potentials in the Variational Principle for a Perfect Fluid

    NASA Astrophysics Data System (ADS)

    Fukagawa, H.; Fujitani, Y.

    2010-09-01

    Equations for a perfect fluid can be obtained by means of the variational principle both in the Lagrangian description and in the Eulerian one. It is known that we need additional fields somehow to describe a rotational isentropic flow in the latter description. We give a simple explanation for these fields; they are introduced to fix both ends of a pathline in the variational calculus. This restriction is imposed in the former description, and should be imposed in the latter description. It is also shown that we can derive a canonical Hamiltonian formulation for a perfect fluid by regarding the velocity field as the input in the framework of control theory.

  8. Cosmological perturbations of a perfect fluid and noncommutative variables

    SciTech Connect

    De Felice, Antonio; Gerard, Jean-Marc; Suyama, Teruaki

    2010-03-15

    We describe the linear cosmological perturbations of a perfect fluid at the level of an action, providing thus an alternative to the standard approach based only on the equations of motion. This action is suited not only to perfect fluids with a barotropic equation of state, but also to those for which the pressure depends on two thermodynamical variables. By quantizing the system we find that (1) some perturbation fields exhibit a noncommutativity quite analogous to the one observed for a charged particle moving in a strong magnetic field, (2) local curvature and pressure perturbations cannot be measured simultaneously, (3) ghosts appear if the null energy condition is violated.

  9. Artificial perfect electric conductor-perfect magnetic conductor anisotropic metasurface for generating orbital angular momentum of microwave with nearly perfect conversion efficiency

    NASA Astrophysics Data System (ADS)

    Chen, Menglin L. N.; Jiang, Li Jun; Sha, Wei E. I.

    2016-02-01

    Orbital angular momentum (OAM) is a promising degree of freedom for fundamental studies in electromagnetics and quantum mechanics. The unlimited state space of OAM shows a great potential to enhance channel capacities of classical and quantum communications. By exploring the Pancharatnam-Berry phase concept and engineering anisotropic scatterers in a metasurface with spatially varying orientations, a plane wave with zero OAM can be converted to a vortex beam carrying nonzero OAM. In this paper, we proposed two types of novel perfect electric conductor-perfect magnetic conductor anisotropic metasurfaces. One is composed of azimuthally continuous loops and the other is constructed by azimuthally discontinuous dipole scatterers. Both types of metasurfaces are mounted on a mushroom-type high impedance surface. Compared to previous metasurface designs for generating OAM, the proposed ones achieve nearly perfect conversion efficiency. In view of the eliminated vertical component of electric field, the continuous metasurface shows very smooth phase pattern at the near-field region, which cannot be achieved by convectional metasurfaces composed of discrete scatterers. On the other hand, the metasurface with discrete dipole scatterers shows a great flexibility to generate OAM with arbitrary topological charges. Our work is fundamentally and practically important to high-performance OAM generation.

  10. Intensity of tennis match play

    PubMed Central

    Fernandez, J; Mendez‐Villanueva, A; Pluim, B M

    2006-01-01

    This review focuses on the characteristics of tennis players during match play and provides a greater insight into the energy demands of tennis. A tennis match often lasts longer than an hour and in some cases more than five hours. During a match there is a combination of periods of maximal or near maximal work and longer periods of moderate and low intensity activity. Match intensity varies considerably depending on the players' level, style, and sex. It is also influenced by factors such as court surface and ball type. This has important implications for the training of tennis players, which should resemble match intensity and include interval training with appropriate work to rest ratios. PMID:16632566

  11. When You Can't Find the Perfect Match: Using the Accumulated Most Similar Design in Case Studies

    ERIC Educational Resources Information Center

    Quinn, John James

    2009-01-01

    What happens when you want to use a most similar case study design for a small-N study, but you cannot find a particular pair of cases where all of the relevant, competing explanations are held constant? It is proposed here that scholars and teachers could employ or teach the "accumulated most-similar/crucial case design." This design…

  12. Bayesian Stereo Matching Method Based on Edge Constraints.

    PubMed

    Li, Jie; Shi, Wenxuan; Deng, Dexiang; Jia, Wenyan; Sun, Mingui

    2012-12-01

    A new global stereo matching method is presented that focuses on the handling of disparity, discontinuity and occlusion. The Bayesian approach is utilized for dense stereo matching problem formulated as a maximum a posteriori Markov Random Field (MAP-MRF) problem. In order to improve stereo matching performance, edges are incorporated into the Bayesian model as a soft constraint. Accelerated belief propagation is applied to obtain the maximum a posteriori estimates in the Markov random field. The proposed algorithm is evaluated using the Middlebury stereo benchmark. Our experimental results comparing with some state-of-the-art stereo matching methods demonstrate that the proposed method provides superior disparity maps with a subpixel precision.

  13. Final report, DOE/industry matching grant

    SciTech Connect

    Kumar, Arvind S.

    2003-02-25

    The Department of Energy/Industry Matching Grant was used to help improve nuclear engineering and science education at the University of Missouri-Rolla. The funds helped in the areas of recruitment and retention. Funds allowed the department to give scholarships to over 100 students (names included). Funds were also used for equipment upgrade and research, including two computers with peripherals, two NaI detectors, and a thermoluminescent dosimeter.

  14. Design of a perfect balance system for active upper-extremity exoskeletons.

    PubMed

    Smith, Richard L; Lobo-Prat, Joan; van der Kooij, Herman; Stienen, Arno H A

    2013-06-01

    Passive gravity compensation in exoskeletons significantly reduces the amount of torque and energy needed from the actuators. So far, no design has been able to achieve perfect balance without compromising the exoskeleton characteristics. Here we propose a novel design that integrates an existing statically-balanced mechanism with two springs and four degrees of freedom into a general-purpose exoskeleton design, that can support any percentage of the combined weight of exoskeleton and arm. As it allows for three rotational degrees of freedom at the shoulder and one at the elbow, it does not compromise exoskeleton characteristics and can be powered with any choice of passive or active actuation method. For instance, with this design a perfectly balanced exoskeleton design with inherently safe, passive actuators on each joint axis becomes possible. The potential reduction in required actuator torque, power and weight, simplification of control, improved dynamic performance, and increased safety margin, all while maintaining perfect balance, are the major advantages of the design, but the integrated systems does add a significant amount of complexity. Future integration in an actual exoskeleton should prove if this tradeoff is beneficial.

  15. Information Theoretic Shape Matching.

    PubMed

    Hasanbelliu, Erion; Giraldo, Luis Sanchez; Príncipe, José C

    2014-12-01

    In this paper, we describe two related algorithms that provide both rigid and non-rigid point set registration with different computational complexity and accuracy. The first algorithm utilizes a nonlinear similarity measure known as correntropy. The measure combines second and high order moments in its decision statistic showing improvements especially in the presence of impulsive noise. The algorithm assumes that the correspondence between the point sets is known, which is determined with the surprise metric. The second algorithm mitigates the need to establish a correspondence by representing the point sets as probability density functions (PDF). The registration problem is then treated as a distribution alignment. The method utilizes the Cauchy-Schwarz divergence to measure the similarity/distance between the point sets and recover the spatial transformation function needed to register them. Both algorithms utilize information theoretic descriptors; however, correntropy works at the realizations level, whereas Cauchy-Schwarz divergence works at the PDF level. This allows correntropy to be less computationally expensive, and for correct correspondence, more accurate. The two algorithms are robust against noise and outliers and perform well under varying levels of distortion. They outperform several well-known and state-of-the-art methods for point set registration.

  16. Contour matching by epipolar geometry

    NASA Astrophysics Data System (ADS)

    Hu, Mao-Lin; Zhang, Damin; Wei, Sui

    2003-09-01

    Matching features computed in images is an important process in multiview image analysis. When the motion between two images is large, the matching problem becomes very difficult. In this paper, we propose a contour matching algorithm based on geometric constraints. With the assumption that the contours are obtained from images taken from a moving camera with static scenes, we apply the epipolar constraint between two sets of contours and compute the corresponding points on the contours. From the initial epipolar constraints obtained from comer point matching, candidate contours are selected according to the epipolar geometry, the linear relation among tangent vectors of the contour. In order to reduce the possibility of false matches, the curvature of the contour of match points on a contour is also used as a selection method. The initial epipolar constraint is refined from the matched sets of contours. The algorithm can be applied to a pair or two pairs of images. All of the processes are fully automatic and successfully implemented and tested with various synthetic images.

  17. A sorting-to-matching method to teach compound matching to sample.

    PubMed

    Farber, Rachel S; Dube, William V; Dickson, Chata A

    2016-06-01

    Individuals with developmental disabilities may fail to attend to multiple features in compound stimuli (e.g., arrays of pictures, letters within words) with detrimental effects on learning. Participants were 5 children with autism spectrum disorder who had low to intermediate accuracy scores (35% to 84%) on a computer-presented compound matching task. Sample stimuli were pairs of icons (e.g., chair-tree), the correct comparison was identical to the sample, and each incorrect comparison had one icon in common with the sample (e.g., chair-sun, airplane-tree). A 5-step tabletop sorting-to-matching training procedure was used to teach compound matching. The first step was sorting 3 single pictures; subsequent steps gradually changed the task to compound matching. If progress stalled, tasks were modified temporarily to prompt observing behavior. After tabletop training, participants were retested on the compound matching task; accuracy improved to at least 95% for all children. This procedure illustrates one way to improve attending to multiple features of compound stimuli.

  18. Perfect Power Prototype for Illinois Institute of Technology

    SciTech Connect

    Shahidehpour, Mohammad

    2014-09-30

    Starting in October 2008, Illinois Institute of Technology (IIT), in collaboration with over 20 participating members, led an extensive effort to develop, demonstrate, promote, and commercialize a microgrid system and offer supporting technologies that will achieve Perfect Power at the main campus of IIT. A Perfect Power system, as defined by the Galvin Electricity Initiative (GEI), is a system that cannot fail to meet the electric needs of the individual end-user. The Principle Investigator of this Perfect Power project was Dr. Mohammad Shahidehpour, Director of the Robert W. Galvin Center for Electricity Innovation at IIT. There were six overall objectives of the Perfect Power project: (1) Demonstrate the higher reliability introduced by the microgrid system at IIT; (2) Demonstrate the economics of microgrid operations; (3) Allow for a decrease of fifty percent (50%) of grid electricity load; (4) Create a permanent twenty percent (20%) decrease in peak load from 2007 level; (5) Defer planned substation through load reduction; (6) Offer a distribution system design that can be replicated in urban communities.

  19. Inhomogeneous generalizations of Bianchi type VIh models with perfect fluid

    NASA Astrophysics Data System (ADS)

    Roy, S. R.; Prasad, A.

    1991-07-01

    Inhomogeneous universes admitting an Abelian G2 of isometry and filled with perfect fluid have been derived. These contain as special cases exact homogeneous universes of Bianchi type VIh. Many of these universes asymptotically tend to homogeneous Bianchi VIh universes. The models have been discussed for their physical and kinematical behaviors.

  20. The Future for Higher Education: Sunrise or Perfect Storm?

    ERIC Educational Resources Information Center

    Hilton, James

    2006-01-01

    In today's knowledge economy, the role of higher education is being redefined--not simply tweaked and fine-tuned but, rather, fundamentally redefined. The author contends that there are at least two ways to frame this future for higher education. The first is to view it as a perfect storm, born from the convergence of numerous disruptive forces.…

  1. The Perfect Storm—Genetic Engineering, Science, and Ethics

    NASA Astrophysics Data System (ADS)

    Rollin, Bernard E.

    2012-07-01

    Uncertainty about ethics has been a major factor in societal rejection of biotechnology. Six factors help create a societal "perfect storm" regarding ethics and biotechnology: Social demand for ethical discussion; societal scientific illiteracy; poor social understanding of ethics; a "Gresham's Law for Ethics;" Scientific Ideology; vested interests dominating ethical discussion. How this can be remedied is discussed.

  2. Unity and Duality in Barack Obama's "A More Perfect Union"

    ERIC Educational Resources Information Center

    Terrill, Robert E.

    2009-01-01

    Faced with a racialized political crisis that threatened to derail his campaign to become the first African American president of the United States, Barack Obama delivered a speech on race titled "A More Perfect Union." He begins by portraying himself as an embodiment of double consciousness, but then invites his audience to share his…

  3. Computation of Thermally Perfect Oblique Shock Wave Properties

    NASA Technical Reports Server (NTRS)

    Tatum, Kenneth E.

    1997-01-01

    A set of compressible flow relations describing flow properties across oblique shock waves, derived for a thermally perfect, calorically imperfect gas, is applied within the existing thermally perfect gas (TPG) computer code. The relations are based upon the specific heat expressed as a polynomial function of temperature. The updated code produces tables of compressible flow properties of oblique shock waves, as well as the original properties of normal shock waves and basic isentropic flow, in a format similar to the tables for normal shock waves found in NACA Rep. 1135. The code results are validated in both the calorically perfect and the calorically imperfect, thermally perfect temperature regimes through comparisons with the theoretical methods of NACA Rep. 1135. The advantages of the TPG code for oblique shock wave calculations, as well as for the properties of isentropic flow and normal shock waves, are its ease of use and its applicability to any type of gas (monatomic, diatomic, triatomic, polyatomic, or any specified mixture thereof).

  4. Designing the Perfect Plant: Activities to Investigate Plant Ecology

    ERIC Educational Resources Information Center

    Lehnhoff, Erik; Woolbaugh, Walt; Rew, Lisa

    2008-01-01

    Plant ecology is an important subject that often receives little attention in middle school, as more time during science classes is devoted to plant biology. Therefore, the authors have developed a series of activities, including a card game--Designing the Perfect Plant--to introduce student's to plant ecology and the ecological trade offs…

  5. Computation of Thermally Perfect Properties of Oblique Shock Waves

    NASA Technical Reports Server (NTRS)

    Tatum, Kenneth E.

    1996-01-01

    A set of compressible flow relations describing flow properties across oblique shock waves, derived for a thermally perfect, calorically imperfect gas, is applied within the existing thermally perfect gas (TPG) computer code. The relations are based upon a value of cp expressed as a polynomial function of temperature. The updated code produces tables of compressible flow properties of oblique shock waves, as well as the original properties of normal shock waves and basic isentropic flow, in a format similar to the tables for normal shock waves found in NACA Rep. 1135. The code results are validated in both the calorically perfect and the calorically imperfect, thermally perfect temperature regimes through comparisons with the theoretical methods of NACA Rep. 1135, and with a state-of-the-art computational fluid dynamics code. The advantages of the TPG code for oblique shock wave calculations, as well as for the properties of isentropic flow and normal shock waves, are its ease of use, and its applicability to any type of gas (monatomic, diatomic, triatomic, polyatomic, or any specified mixture thereof).

  6. Creating The Perfect Liquid In Heavy-Ion Collisions

    SciTech Connect

    Jacak, B.; Steinberg, P.

    2010-05-01

    In 2005 the four experimental groups at Brookhaven National Laboratory's Relativistic Heavy Ion Collider (RHIC) announced that collisions of gold nuclei at ultrarelativistic energies produced a 'perfect liquid' of quarks and gluons. That's something quite different from the gaseous quark-gluon state theorists and experimenters were expecting from quantum chromodynamics, the standard theory of the strong interaction.

  7. The Perfect Storm--Genetic Engineering, Science, and Ethics

    ERIC Educational Resources Information Center

    Rollin, Bernard E.

    2014-01-01

    Uncertainty about ethics has been a major factor in societal rejection of biotechnology. Six factors help create a societal "perfect storm" regarding ethics and biotechnology: Social demand for ethical discussion; societal scientific illiteracy; poor social understanding of ethics; a "Gresham's Law for Ethics;" Scientific…

  8. Virtually No Evidence for Virtually Perfect Time-Sharing

    ERIC Educational Resources Information Center

    Tombu, Michael; Jolicoeur, Pierre

    2004-01-01

    An examination of previous claims for virtually perfect time-sharing in dual-task situations reveals confounding effects that may have obscured dual-task interference. Two experiments are conducted in which these confounding effects are minimized, revealing statistically significant dual-task interference. These results support the hypothesis that…

  9. America's Perfect Storm: Three Forces Changing Our Nation's Future

    ERIC Educational Resources Information Center

    Kirsch, Irwin; Braun, Henry; Yamamoto, Kentaro; Sum, Andrew

    2007-01-01

    The authors offer the image of our nation as a nautical convoy. Some boats are large, well built, and able to ride out the heaviest of turbulent seas. Others are smaller, but still quite sturdy, and able to survive. Many however, are fragile, meagerly equipped, and easily capsized in rough waters. This convoy is in the midst of a perfect storm…

  10. MATCHING IN INFORMAL FINANCIAL INSTITUTIONS

    PubMed Central

    Eeckhout, Jan; Munshi, Kaivan

    2013-01-01

    This paper analyzes an informal financial institution that brings heterogeneous agents together in groups. We analyze decentralized matching into these groups, and the equilibrium composition of participants that consequently arises. We find that participants sort remarkably well across the competing groups, and that they re-sort immediately following an unexpected exogenous regulatory change. These findings suggest that the competitive matching model might have applicability and bite in other settings where matching is an important equilibrium phenomenon. (JEL: O12, O17, G20, D40) PMID:24027491

  11. Adaptive and compressive matched field processing.

    PubMed

    Gemba, Kay L; Hodgkiss, William S; Gerstoft, Peter

    2017-01-01

    Matched field processing is a generalized beamforming method that matches received array data to a dictionary of replica vectors in order to locate one or more sources. Its solution set is sparse since there are considerably fewer sources than replicas. Using compressive sensing (CS) implemented using basis pursuit, the matched field problem is reformulated as an underdetermined, convex optimization problem. CS estimates the unknown source amplitudes using the replica dictionary to best explain the data, subject to a row-sparsity constraint. This constraint selects the best matching replicas within the dictionary when using multiple observations and/or frequencies. For a single source, theory and simulations show that the performance of CS and the Bartlett processor are equivalent for any number of snapshots. Contrary to most adaptive processors, CS also can accommodate coherent sources. For a single and multiple incoherent sources, simulations indicate that CS offers modest localization performance improvement over the adaptive white noise constraint processor. SWellEx-96 experiment data results show comparable performance for both processors when localizing a weaker source in the presence of a stronger source. Moreover, CS often displays less ambiguity, demonstrating it is robust to data-replica mismatch.

  12. Bonding and impedance matching of acoustic transducers using silver epoxy.

    PubMed

    Son, Kyu Tak; Lee, Chin C

    2012-04-01

    Silver epoxy was selected to bond transducer plates on glass substrates. The properties and thickness of the bonding medium affect the electrical input impedance of the transducer. Thus, the thickness of the silver epoxy bonding layer was used as a design parameter to optimize the structure for the transducer input impedance to match the 50 Ω output impedance of most radio frequency (RF) generators. Simulation and experimental results show that nearly perfect matching is achieved without using any matching circuit. At the matching condition, the transducer operates at a frequency band a little bit below the half-wavelength resonant frequency of the piezoelectric plate. In experiments, lead titanate (PT) piezoelectric plates were employed. Both full-size, 11.5 mm × 2 mm × 0.4 mm, and half-size, 5.75 mm × 2 mm × 0.4 mm, can be well matched using optimal silver epoxy thickness. The transducer assemblies demonstrate high efficiency. The conversion loss from electrical power to acoustic power in soda-lime glass is 4.3 dB. This loss is low considering the fact that the transducers operate at off-resonance by 12%. With proper choice of silver epoxy thickness, the transducer can be matched at the fundamental, the 3rd and 5th harmonic frequencies. This leads to the possible realization of triple-band transducers. Reliability was assessed with thermal cycling test according to Telcordia GR-468-Core recommendation. Of the 30 transducer assemblies tested, none broke until 2900 cycles and 27 have sustained beyond 4050 cycles.

  13. Matching Faces Against the Clock

    PubMed Central

    Fysh, Matthew; Cross, Katie; Watts, Rebecca

    2016-01-01

    This study examined the effect of time pressure on face-matching accuracy. Across two experiments, observers decided whether pairs of faces depict one person or different people. Time pressure was exerted via two additional displays, which were constantly updated to inform observers on whether they were on track to meet or miss a time target. In this paradigm, faces were matched under increasing or decreasing (Experiment 1) and constant time pressure (Experiment 2), which varied from 10 to 2 seconds. In both experiments, time pressure reduced accuracy, but the point at which this declined varied from 8 to 2 seconds. A separate match response bias was found, which developed over the course of the experiments. These results indicate that both time pressure and the repetitive nature of face matching are detrimental to performance. PMID:27757219

  14. Matching Network For Microwave Preamplifier

    NASA Technical Reports Server (NTRS)

    Sifri, Jack D.

    1988-01-01

    Stable operation and broadband, optimum noise performance achieved. Amplifier designed by new method of matching input impedance for optimum noise figure and stability. Output more nearly constant over wider frequency range.

  15. Designing self-matching linacs

    SciTech Connect

    Mills, R.S.; Crandall, K.R.; Farrell, J.A.

    1984-01-01

    The present trend in ion-linac design is to begin with a radio-frequency quadrupole (RFQ) linac followed by one or more drift-tube linac (DTL) tanks in which permanent-magnet quadrupoles are used for transverse focusing. The lack of adjustable elements (knobs) strongly suggests that one should seek linac designs with intertank matching solutions that are insensitive to beam currents and emittances, which can be accomplished if there are no sharp discontinuities in the focusing properties along the entire linac. Guidelines are presented for linac design and describe techniques for longitudinal as well as transverse matching between tanks. For a wide range of beam currents and emittances, a beam matched at the entrance to the RFQ should remain well matched throughout the entire linac.

  16. A THz plasmonics perfect absorber and Fabry-Perot cavity mechanism (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Zhou, Jiangfeng; Bhattarai, Khagendra; Silva, Sinhara; Jeon, Jiyeon; Kim, Junoh; Lee, Sang Jun; Ku, Zahyun

    2016-10-01

    The plasmonic metamaterial perfect absorber (MPA) is a recently developed branch of metamaterial which exhibits nearly unity absorption within certain frequency range.[1-6] The optically thin MPA possesses characteristic features of angular-independence, high Q-factor and strong field localization that have inspired a wide range of applications including electromagnetic wave absorption,[3, 7, 8] spatial[6] and spectral[5] modulation of light,[9] selective thermal emission,[9] thermal detecting[10] and refractive index sensing for gas[11] and liquid[12, 13] targets. In this work, we demonstrate a MPA working at terahertz (THz) regime and characterize it using an ultrafast THz time-domain spectroscopy (THz-TDS). Our study reveal an ultra-thin Fabry-Perot cavity mechanism compared to the impedance matching mechanism widely adopted in previous study [1-6]. Our results also shows higher-order resonances when the cavities length increases. These higher order modes exhibits much larger Q-factor that can benefit potential sensing and imaging applications. [1] C. M. Watts, X. L. Liu, and W. J. Padilla, "Metamaterial Electromagnetic Wave Absorbers," Advanced Materials, vol. 24, pp. 98-120, Jun 19 2012. [2] M. Hedayati, F. Faupel, and M. Elbahri, "Review of Plasmonic Nanocomposite Metamaterial Absorber," Materials, vol. 7, pp. 1221-1248, 2014. [3] N. I. Landy, S. Sajuyigbe, J. J. Mock, D. R. Smith, and W. J. Padilla, "Perfect metamaterial absorber," Physical Review Letters, vol. 100, p. 207402, May 23 2008. [4] H. R. Seren, G. R. Keiser, L. Cao, J. Zhang, A. C. Strikwerda, K. Fan, et al., "Optically Modulated Multiband Terahertz Perfect Absorber," Advanced Optical Materials, vol. 2, pp. 1221-1226, 2014. [5] D. Shrekenhamer, J. Montoya, S. Krishna, and W. J. Padilla, "Four-Color Metamaterial Absorber THz Spatial Light Modulator," Advanced Optical Materials, vol. 1, pp. 905-909, 2013. [6] S. Savo, D. Shrekenhamer, and W. J. Padilla, "Liquid Crystal Metamaterial Absorber Spatial

  17. Matching games with partial information

    NASA Astrophysics Data System (ADS)

    Laureti, Paolo; Zhang, Yi-Cheng

    2003-06-01

    We analyze different ways of pairing agents in a bipartite matching problem, with regard to its scaling properties and to the distribution of individual “satisfactions”. Then we explore the role of partial information and bounded rationality in a generalized Marriage Problem, comparing the benefits obtained by self-searching and by a matchmaker. Finally we propose a modified matching game intended to mimic the way consumers’ information makes firms to enhance the quality of their products in a competitive market.

  18. A retrospective evaluation of the Perfecting Patient Care University training program for health care organizations.

    PubMed

    Morganti, Kristy Gonzalez; Lovejoy, Susan; Beckjord, Ellen Burke; Haviland, Amelia M; Haas, Ann C; Farley, Donna O

    2014-01-01

    This study evaluated how the Perfecting Patient Care (PPC) University, a quality improvement (QI) training program for health care leaders and clinicians, affected the ability of organizations to improve the health care they provide. This training program teaches improvement methods based on Lean concepts and principles of the Toyota Production System and is offered in several formats. A retrospective evaluation was performed that gathered data on training, other process factors, and outcomes after staff completed the PPC training. A majority of respondents reported gaining QI competencies and cultural achievements from the training. Organizations had high average scores for the success measures of "outcomes improved" and "sustainable monitoring" but lower scores for diffusion of QI efforts. Total training dosage was significantly associated with the measures of QI success. This evaluation provides evidence that organizations gained the PPC competencies and cultural achievements and that training dosage is a driver of QI success.

  19. Generating moment matching scenarios using optimization techniques

    SciTech Connect

    Mehrotra, Sanjay; Papp, Dávid

    2013-05-16

    An optimization based method is proposed to generate moment matching scenarios for numerical integration and its use in stochastic programming. The main advantage of the method is its flexibility: it can generate scenarios matching any prescribed set of moments of the underlying distribution rather than matching all moments up to a certain order, and the distribution can be defined over an arbitrary set. This allows for a reduction in the number of scenarios and allows the scenarios to be better tailored to the problem at hand. The method is based on a semi-infinite linear programming formulation of the problem that is shown to be solvable with polynomial iteration complexity. A practical column generation method is implemented. The column generation subproblems are polynomial optimization problems; however, they need not be solved to optimality. It is found that the columns in the column generation approach can be efficiently generated by random sampling. The number of scenarios generated matches a lower bound of Tchakaloff's. The rate of convergence of the approximation error is established for continuous integrands, and an improved bound is given for smooth integrands. Extensive numerical experiments are presented in which variants of the proposed method are compared to Monte Carlo and quasi-Monte Carlo methods on both numerical integration problems and stochastic optimization problems. The benefits of being able to match any prescribed set of moments, rather than all moments up to a certain order, is also demonstrated using optimization problems with 100-dimensional random vectors. Here, empirical results show that the proposed approach outperforms Monte Carlo and quasi-Monte Carlo based approaches on the tested problems.

  20. Generating moment matching scenarios using optimization techniques

    DOE PAGES

    Mehrotra, Sanjay; Papp, Dávid

    2013-05-16

    An optimization based method is proposed to generate moment matching scenarios for numerical integration and its use in stochastic programming. The main advantage of the method is its flexibility: it can generate scenarios matching any prescribed set of moments of the underlying distribution rather than matching all moments up to a certain order, and the distribution can be defined over an arbitrary set. This allows for a reduction in the number of scenarios and allows the scenarios to be better tailored to the problem at hand. The method is based on a semi-infinite linear programming formulation of the problem thatmore » is shown to be solvable with polynomial iteration complexity. A practical column generation method is implemented. The column generation subproblems are polynomial optimization problems; however, they need not be solved to optimality. It is found that the columns in the column generation approach can be efficiently generated by random sampling. The number of scenarios generated matches a lower bound of Tchakaloff's. The rate of convergence of the approximation error is established for continuous integrands, and an improved bound is given for smooth integrands. Extensive numerical experiments are presented in which variants of the proposed method are compared to Monte Carlo and quasi-Monte Carlo methods on both numerical integration problems and stochastic optimization problems. The benefits of being able to match any prescribed set of moments, rather than all moments up to a certain order, is also demonstrated using optimization problems with 100-dimensional random vectors. Here, empirical results show that the proposed approach outperforms Monte Carlo and quasi-Monte Carlo based approaches on the tested problems.« less

  1. Theoretical and thermal characterization of a wideband perfect absorber for application in solar cells

    NASA Astrophysics Data System (ADS)

    Rufangura, Patrick; Sabah, Cumali

    2016-12-01

    This paper suggests a metamaterial (MTM) absorber structure to be used for efficiency improved solar cell. The proposed MTM absorber consists of the topmost three concentric circular ring resonators, and a ground metal plane sandwiched to the top layer with a dielectric spacer. Numerical simulation and theoretical (interference theory) studies on the proposed design show a wideband with near-perfect (>99%) absorption response in the visible frequency region of the solar spectrum. Thermal characterization of the suggested design is also conducted in order to investigate its absorption capability at different temperatures. The proposed MTM absorber design is believed to be an outstanding candidate toward high-efficiency solar photovoltaic cell.

  2. Wideband antireflective circular polarizer exhibiting a perfect dark state in organic light-emitting-diode display.

    PubMed

    Kim, Bong Choon; Lim, Young Jin; Song, Je Hoon; Lee, Jun Hee; Jeong, Kwang-Un; Lee, Joong Hee; Lee, Gi-Dong; Lee, Seung Hee

    2014-12-15

    We proposed wideband antireflective circular polarizer for realizing a true black state in all viewing directions in organic light-emitting-diode displays (OLEDs). Present commercialized wideband circular polarizer consisted of a half wave and a quarter wave plates having the refractive index parameter (Nz) of 1.5 in both films exhibits light leakage in the oblique viewing directions, deteriorating image quality of a black state. We evaluated Nzs of both films and proposed a new wideband antireflective circular polarizer with a perfect dark state in all viewing directions with Nz = 0.5 in both plates, which will greatly improve image quality of OLEDs.

  3. Perfect optical vortex enhanced surface plasmon excitation for plasmonic structured illumination microscopy imaging

    NASA Astrophysics Data System (ADS)

    Zhang, Chonglei; Min, Changjun; Du, Luping; Yuan, X.-C.

    2016-05-01

    We propose an all-optical technique for plasmonic structured illumination microscopy (PSIM) with perfect optical vortex (POV). POV can improve the efficiency of the excitation of surface plasma and reduce the background noise of the excited fluorescence. The plasmonic standing wave patterns are excited by POV with fractional topological charges for accurate phase shift of {-2π/3, 0, and 2π/3}. The imaging resolution of less than 200 nm was produced. This PSIM technique is expected to be used as a wide field, super resolution imaging technique in dynamic biological imaging.

  4. 76 FR 5235 - Privacy Act of 1974, as Amended; Computer Matching Program (SSA Internal Match)-Match Number 1014

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-28

    ... ADMINISTRATION Privacy Act of 1974, as Amended; Computer Matching Program (SSA Internal Match)--Match Number 1014 AGENCY: Social Security Administration (SSA) ACTION: Notice of a new computer matching program. SUMMARY... computer matching program that we are conducting with ourselves. DATES: We will file a report of...

  5. Robust spatiotemporal matching of electronic slides to presentation videos.

    PubMed

    Fan, Quanfu; Barnard, Kobus; Amir, Arnon; Efrat, Alon

    2011-08-01

    We describe a robust and efficient method for automatically matching and time-aligning electronic slides to videos of corresponding presentations. Matching electronic slides to videos provides new methods for indexing, searching, and browsing videos in distance-learning applications. However, robust automatic matching is challenging due to varied frame composition, slide distortion, camera movement, low-quality video capture, and arbitrary slides sequence. Our fully automatic approach combines image-based matching of slide to video frames with a temporal model for slide changes and camera events. To address these challenges, we begin by extracting scale-invariant feature-transformation (SIFT) keypoints from both slides and video frames, and matching them subject to a consistent projective transformation (homography) by using random sample consensus (RANSAC). We use the initial set of matches to construct a background model and a binary classifier for separating video frames showing slides from those without. We then introduce a new matching scheme for exploiting less distinctive SIFT keypoints that enables us to tackle more difficult images. Finally, we improve upon the matching based on visual information by using estimated matching probabilities as part of a hidden Markov model (HMM) that integrates temporal information and detected camera operations. Detailed quantitative experiments characterize each part of our approach and demonstrate an average accuracy of over 95% in 13 presentation videos.

  6. 3' UTR seed matches, but not overall identity, are associated with RNAi off-targets.

    PubMed

    Birmingham, Amanda; Anderson, Emily M; Reynolds, Angela; Ilsley-Tyree, Diane; Leake, Devin; Fedorov, Yuriy; Baskerville, Scott; Maksimova, Elena; Robinson, Kathryn; Karpilow, Jon; Marshall, William S; Khvorova, Anastasia

    2006-03-01

    Off-target gene silencing can present a notable challenge in the interpretation of data from large-scale RNA interference (RNAi) screens. We performed a detailed analysis of off-targeted genes identified by expression profiling of human cells transfected with small interfering RNA (siRNA). Contrary to common assumption, analysis of the subsequent off-target gene database showed that overall identity makes little or no contribution to determining whether the expression of a particular gene will be affected by a given siRNA, except for near-perfect matches. Instead, off-targeting is associated with the presence of one or more perfect 3' untranslated region (UTR) matches with the hexamer or heptamer seed region (positions 2-7 or 2-8) of the antisense strand of the siRNA. These findings have strong implications for future siRNA design and the application of RNAi in high-throughput screening and therapeutic development.

  7. Efficient Scheme for Perfect Collective Einstein-Podolsky-Rosen Steering

    PubMed Central

    Wang, M.; Gong, Q. H.; Ficek, Z.; He, Q. Y.

    2015-01-01

    A practical scheme for the demonstration of perfect one-sided device-independent quantum secret sharing is proposed. The scheme involves a three-mode optomechanical system in which a pair of independent cavity modes is driven by short laser pulses and interact with a movable mirror. We demonstrate that by tuning the laser frequency to the blue (anti-Stokes) sideband of the average frequency of the cavity modes, the modes become mutually coherent and then may collectively steer the mirror mode to a perfect Einstein-Podolsky-Rosen state. The scheme is shown to be experimentally feasible, it is robust against the frequency difference between the modes, mechanical thermal noise and damping, and coupling strengths of the cavity modes to the mirror. PMID:26212901

  8. Nonlocal memory effects allow perfect teleportation with mixed states.

    PubMed

    Laine, Elsi-Mari; Breuer, Heinz-Peter; Piilo, Jyrki

    2014-04-09

    One of the most striking consequences of quantum physics is quantum teleportation - the possibility to transfer quantum states over arbitrary distances. Since its theoretical introduction, teleportation has been demonstrated experimentally up to the distance of 143 km. In the original proposal two parties share a maximally entangled quantum state acting as a resource for the teleportation task. If, however, the state is influenced by decoherence, perfect teleportation can no longer be accomplished. Therefore, one of the current major challenges in accomplishing teleportation over long distances is to overcome the limitations imposed by decoherence and the subsequent mixedness of the resource state. Here we show that, in the presence of nonlocal memory effects, perfect quantum teleportation can be achieved even with mixed photon polarisation states. Our results imply that memory effects can be exploited in harnessing noisy quantum systems for quantum communication and that non-Markovianity is a resource for quantum information tasks.

  9. Miniaturization for ultrathin metamaterial perfect absorber in the VHF band.

    PubMed

    Khuyen, Bui Xuan; Tung, Bui Son; Yoo, Young Joon; Kim, Young Ju; Kim, Ki Won; Chen, Liang-Yao; Lam, Vu Dinh; Lee, YoungPak

    2017-03-22

    An efficient resolution for ultrathin metamaterial perfect absorber (MPA) is proposed and demonstrated in the VHF radio band (30-300 MHz). By adjusting the lumped capacitors and the through vertical interconnects, the absorber is miniaturized to be only λ/816 and λ/84 for its thickness and periodicity with respect to the operating wavelength (at 102 MHz), respectively. The detailed simulation and calculation show that the MPA can maintain an absorption rate over 90% in a certain range of incident angle and with a wide variation of capacitance. Additionally, we utilized the advantages of the initial single-band structure to realize a nearly perfect dual-band absorber in the same range. The results were confirmed by both simulation and experiment at oblique incidence angles up to 50°. Our work is expected to contribute to the actualization of future metamaterial-based devices working at radio frequency.

  10. Miniaturization for ultrathin metamaterial perfect absorber in the VHF band

    PubMed Central

    Khuyen, Bui Xuan; Tung, Bui Son; Yoo, Young Joon; Kim, Young Ju; Kim, Ki Won; Chen, Liang-Yao; Lam, Vu Dinh; Lee, YoungPak

    2017-01-01

    An efficient resolution for ultrathin metamaterial perfect absorber (MPA) is proposed and demonstrated in the VHF radio band (30–300 MHz). By adjusting the lumped capacitors and the through vertical interconnects, the absorber is miniaturized to be only λ/816 and λ/84 for its thickness and periodicity with respect to the operating wavelength (at 102 MHz), respectively. The detailed simulation and calculation show that the MPA can maintain an absorption rate over 90% in a certain range of incident angle and with a wide variation of capacitance. Additionally, we utilized the advantages of the initial single-band structure to realize a nearly perfect dual-band absorber in the same range. The results were confirmed by both simulation and experiment at oblique incidence angles up to 50°. Our work is expected to contribute to the actualization of future metamaterial-based devices working at radio frequency. PMID:28327658

  11. Applying Gradient Expansion to a Perfect Fluid and Higher Dimensions

    NASA Astrophysics Data System (ADS)

    Chiba, Takeshi

    1996-09-01

    We examine the nonlinear evolution of two types of spacetime by solving the Hamilton-Jacobi equation by the gradient expansion method to investigate the validity and limitation of the method itself. The first type is the nonlinear evolution of spacetime for an irrotational perfect fluid, and the second type is for an irrotational dust or an scalar field with an exponential potential inn-dimensional space. We find a recursion relation for the generating functional. Taking the comoving coordinate, the three-metric for perfect fluid is found up to the third order. The expression for the three-metric is in agreement with that of Comer et al. but the numerical coefficient is slightly different because of the different choice of coordinate condition. For a scalar field with an exponential potential in higher dimension, inhomogeneities decay during inflationary phase. The (n+1)-dimensional axisymmetric Szekeres solution is easily found as a byproduct.

  12. Perfectly absorbing ultra thin interference coatings for hydrogen sensing.

    PubMed

    Serhatlioglu, Murat; Ayas, Sencer; Biyikli, Necmi; Dana, Aykutlu; Solmaz, Mehmet E

    2016-04-15

    Here we numerically demonstrate a straightforward method for optical detection of hydrogen gas by means of absorption reduction and colorimetric indication. A perfectly absorbing metal-insulator-metal (MIM) thin film interference structure is constructed using a silver metal back reflector, silicon dioxide insulator, and palladium as the upper metal layer and hydrogen catalyst. The thickness of silicon dioxide allows the maximizing of the electric field intensity at the Air/SiO2 interface at the quarter wavelengths and enabling perfect absorption with the help of highly absorptive palladium thin film (∼7 nm). While the exposure of the MIM structure to H2 moderately increases reflection, the relative intensity contrast due to formation of metal hydride is extensive. By modifying the insulator film thickness and hence the spectral absorption, the color is tuned and eye-visible results are obtained.

  13. Nonlocal memory effects allow perfect teleportation with mixed states

    PubMed Central

    Laine, Elsi-Mari; Breuer, Heinz-Peter; Piilo, Jyrki

    2014-01-01

    One of the most striking consequences of quantum physics is quantum teleportation – the possibility to transfer quantum states over arbitrary distances. Since its theoretical introduction, teleportation has been demonstrated experimentally up to the distance of 143 km. In the original proposal two parties share a maximally entangled quantum state acting as a resource for the teleportation task. If, however, the state is influenced by decoherence, perfect teleportation can no longer be accomplished. Therefore, one of the current major challenges in accomplishing teleportation over long distances is to overcome the limitations imposed by decoherence and the subsequent mixedness of the resource state. Here we show that, in the presence of nonlocal memory effects, perfect quantum teleportation can be achieved even with mixed photon polarisation states. Our results imply that memory effects can be exploited in harnessing noisy quantum systems for quantum communication and that non-Markovianity is a resource for quantum information tasks. PMID:24714695

  14. Perfect commuting-operator strategies for linear system games

    NASA Astrophysics Data System (ADS)

    Cleve, Richard; Liu, Li; Slofstra, William

    2017-01-01

    Linear system games are a generalization of Mermin's magic square game introduced by Cleve and Mittal. They show that perfect strategies for linear system games in the tensor-product model of entanglement correspond to finite-dimensional operator solutions of a certain set of non-commutative equations. We investigate linear system games in the commuting-operator model of entanglement, where Alice and Bob's measurement operators act on a joint Hilbert space, and Alice's operators must commute with Bob's operators. We show that perfect strategies in this model correspond to possibly infinite-dimensional operator solutions of the non-commutative equations. The proof is based around a finitely presented group associated with the linear system which arises from the non-commutative equations.

  15. Dynamics of non-minimally coupled perfect fluids

    SciTech Connect

    Bettoni, Dario; Liberati, Stefano E-mail: liberati@sissa.it

    2015-08-01

    We present a general formulation of the theory for a non-minimally coupled perfect fluid in which both conformal and disformal couplings are present. We discuss how such non-minimal coupling is compatible with the assumptions of a perfect fluid and derive both the Einstein and the fluid equations for such model. We found that, while the Euler equation is significantly modified with the introduction of an extra force related to the local gradients of the curvature, the continuity equation is unaltered, thus allowing for the definition of conserved quantities along the fluid flow. As an application to cosmology and astrophysics we compute the effects of the non-minimal coupling on a Friedmann-Lemaȋtre-Robertson-Walker metric at both background and linear perturbation level and on the Newtonian limit of our theory.

  16. Perfect Thermal Emission by Nanoscale Transmission Line Resonators.

    PubMed

    Liu, Baoan; Gong, Wei; Yu, Bowen; Li, Pengfei; Shen, Sheng

    2017-02-08

    Thermal radiation with a narrow-band emission spectrum is of great importance in a variety of applications such as infrared sensing, thermophotovoltaics, radiation cooling, and thermal circuits. Although resonant nanophotonic structures such as metamaterials and nanocavities have been demonstrated to achieve the narrow-band thermal emission, maximizing their radiation power toward perfect emission still remains challenging. Here, based on the recently developed quasi-normal mode theory, we prove that thermal emission from a nanoscale transmission line resonator can always be maximized by tuning the waveguiding loss of the resonator or bending the structure. By use of nanoscale transmission line resonators as basic building blocks, we experimentally demonstrate a new type of macroscopic perfect and tunable thermal emitters. Our experimental demonstration in conjunction with the general theoretical framework from the quasi-normal mode theory lays the foundation for designing tunable narrow-band thermal emitters with applications in thermal infrared light sources, thermal management, and infrared sensing and imaging.

  17. Efficient Scheme for Perfect Collective Einstein-Podolsky-Rosen Steering.

    PubMed

    Wang, M; Gong, Q H; Ficek, Z; He, Q Y

    2015-07-27

    A practical scheme for the demonstration of perfect one-sided device-independent quantum secret sharing is proposed. The scheme involves a three-mode optomechanical system in which a pair of independent cavity modes is driven by short laser pulses and interact with a movable mirror. We demonstrate that by tuning the laser frequency to the blue (anti-Stokes) sideband of the average frequency of the cavity modes, the modes become mutually coherent and then may collectively steer the mirror mode to a perfect Einstein-Podolsky-Rosen state. The scheme is shown to be experimentally feasible, it is robust against the frequency difference between the modes, mechanical thermal noise and damping, and coupling strengths of the cavity modes to the mirror.

  18. Efficient Scheme for Perfect Collective Einstein-Podolsky-Rosen Steering

    NASA Astrophysics Data System (ADS)

    Wang, M.; Gong, Q. H.; Ficek, Z.; He, Q. Y.

    2015-07-01

    A practical scheme for the demonstration of perfect one-sided device-independent quantum secret sharing is proposed. The scheme involves a three-mode optomechanical system in which a pair of independent cavity modes is driven by short laser pulses and interact with a movable mirror. We demonstrate that by tuning the laser frequency to the blue (anti-Stokes) sideband of the average frequency of the cavity modes, the modes become mutually coherent and then may collectively steer the mirror mode to a perfect Einstein-Podolsky-Rosen state. The scheme is shown to be experimentally feasible, it is robust against the frequency difference between the modes, mechanical thermal noise and damping, and coupling strengths of the cavity modes to the mirror.

  19. Holographic perfect shuffle permutation element for a miniaturized switching network

    NASA Astrophysics Data System (ADS)

    Kobolla, H.; Schmidt, J.; Gluch, E.; Schwider, J.

    1995-06-01

    A holographic perfect shuffle element with 80 channels for a miniaturized switching network is reported. An array of vertical-cavity, surface-emitting lasers is used as a transmitter. The whole permutation is carried out totally in glass. The 80 channels are permuted within a rectangle with a volume of 3 mm \\times 4 mm \\times 2 mm. Four planes of stacked volume holograms recorded in dichromated gelatin form this perfect shuffle element with an angular spectrum between 7 deg and 35 deg. Changes in the wavelength of the diode lasers to Delta lambda = +/-10 nm can be compensated with this setup. The overall efficiency per channel lies between 40% and 60%. When Fresnel reflections and absorption are taken into account, a transmission per hologram between 78% and 90% is achieved.

  20. Miniaturization for ultrathin metamaterial perfect absorber in the VHF band

    NASA Astrophysics Data System (ADS)

    Khuyen, Bui Xuan; Tung, Bui Son; Yoo, Young Joon; Kim, Young Ju; Kim, Ki Won; Chen, Liang-Yao; Lam, Vu Dinh; Lee, Youngpak

    2017-03-01

    An efficient resolution for ultrathin metamaterial perfect absorber (MPA) is proposed and demonstrated in the VHF radio band (30–300 MHz). By adjusting the lumped capacitors and the through vertical interconnects, the absorber is miniaturized to be only λ/816 and λ/84 for its thickness and periodicity with respect to the operating wavelength (at 102 MHz), respectively. The detailed simulation and calculation show that the MPA can maintain an absorption rate over 90% in a certain range of incident angle and with a wide variation of capacitance. Additionally, we utilized the advantages of the initial single-band structure to realize a nearly perfect dual-band absorber in the same range. The results were confirmed by both simulation and experiment at oblique incidence angles up to 50°. Our work is expected to contribute to the actualization of future metamaterial-based devices working at radio frequency.

  1. Tunable enhanced optical absorption of graphene using plasmonic perfect absorbers

    SciTech Connect

    Cai, Yijun; Zhu, Jinfeng; Liu, Qing Huo

    2015-01-26

    Enhancement and manipulation of light absorption in graphene is a significant issue for applications of graphene-based optoelectronic devices. In order to achieve this purpose in the visible region, we demonstrate a design of a graphene optical absorber inspired by metal-dielectric-metal metamaterial for perfect absorption of electromagnetic waves. The optical absorbance ratios of single and three atomic layer graphene are enhanced up to 37.5% and 64.8%, respectively. The graphene absorber shows polarization-dependence and tolerates a wide range of incident angles. Furthermore, the peak position and bandwidth of graphene absorption spectra are tunable in a wide wavelength range through a specific structural configuration. These results imply that graphene in combination with plasmonic perfect absorbers have a promising potential for developing advanced nanophotonic devices.

  2. Perfect fluids in the Einstein-Cartan theory

    NASA Technical Reports Server (NTRS)

    Ray, J. R.; Smalley, L. J.

    1982-01-01

    It is pointed out that whereas most of the discussion of the Einstein-Cartan (EC) theory involves the relationship between gravitation and elementary particles, it is possible that the theory, if correct, may be important in certain extreme astrophysical and cosmological problems. The latter would include something like the collapse of a spinning star or an early universe with spin. A set of equations that describe a macroscopic perfect fluid in the EC theory is derived and examined. The equations are derived starting from the fundamental variational principle for a perfect fluid in general relativity. A brief review of the study by Ray (1972) is included, and the results for the EC theory are presented.

  3. Enhancement in second harmonic generation efficiency, laser damage threshold and optical transparency of Mn 2+ doped L-alanine crystals: A correlation with crystalline perfection

    NASA Astrophysics Data System (ADS)

    Kushwaha, S. K.; Rathee, S. P.; Maurya, K. K.; Bhagavannarayana, G.

    2011-08-01

    Effect on crystalline perfection, second harmonic generation (SHG) efficiency, laser damage threshold (LDT) and optical transparency due to Mn 2+ doping in L-alanine crystals has been investigated. The crystalline perfection of pure and doped crystals was evaluated by high-resolution X-ray diffractometry, which revealed the improvement in the crystalline perfection at low and moderate doping concentrations. At moderate and high concentrations, the Mn 2+ ions were found to be incorporated predominantly at the interstitial sites of the crystalline matrix. The actual incorporated amount of dopants in the crystals was analyzed by atomic absorption spectroscopy. The optical transparency, SHG efficiency, and laser damage threshold of the grown crystals with different concentrations of Mn 2+ were investigated. From these studies it is revealed that Mn 2+ doping lead to a considerable enhancement in the measured nonlinear optical properties with a correlation on crystalline perfection.

  4. Understanding Y haplotype matching probability.

    PubMed

    Brenner, Charles H

    2014-01-01

    The Y haplotype population-genetic terrain is better explored from a fresh perspective rather than by analogy with the more familiar autosomal ideas. For haplotype matching probabilities, versus for autosomal matching probabilities, explicit attention to modelling - such as how evolution got us where we are - is much more important while consideration of population frequency is much less so. This paper explores, extends, and explains some of the concepts of "Fundamental problem of forensic mathematics - the evidential strength of a rare haplotype match". That earlier paper presented and validated a "kappa method" formula for the evidential strength when a suspect matches a previously unseen haplotype (such as a Y-haplotype) at the crime scene. Mathematical implications of the kappa method are intuitive and reasonable. Suspicions to the contrary raised in rest on elementary errors. Critical to deriving the kappa method or any sensible evidential calculation is understanding that thinking about haplotype population frequency is a red herring; the pivotal question is one of matching probability. But confusion between the two is unfortunately institutionalized in much of the forensic world. Examples make clear why (matching) probability is not (population) frequency and why uncertainty intervals on matching probabilities are merely confused thinking. Forensic matching calculations should be based on a model, on stipulated premises. The model inevitably only approximates reality, and any error in the results comes only from error in the model, the inexactness of the approximation. Sampling variation does not measure that inexactness and hence is not helpful in explaining evidence and is in fact an impediment. Alternative haplotype matching probability approaches that various authors have considered are reviewed. Some are based on no model and cannot be taken seriously. For the others, some evaluation of the models is discussed. Recent evidence supports the adequacy of

  5. Overlapped illusion optics: a perfect lens brings a brighter feature

    NASA Astrophysics Data System (ADS)

    Xu, Yadong; Du, Shengwang; Gao, Lei; Chen, Huanyang

    2011-02-01

    In this paper, we show that a perfect lens can be employed to make multiple objects appear like only one object in the far field, leading to a new concept in illusion optics. Numerical simulations have been performed to verify the functionalities for both passive and active objects. The conceptual device can be utilized to enhance the illumination brightness for both incoherent and coherent systems.

  6. A quantitative comparison of corrective and perfective maintenance

    NASA Technical Reports Server (NTRS)

    Henry, Joel; Cain, James

    1994-01-01

    This paper presents a quantitative comparison of corrective and perfective software maintenance activities. The comparison utilizes basic data collected throughout the maintenance process. The data collected are extensive and allow the impact of both types of maintenance to be quantitatively evaluated and compared. Basic statistical techniques test relationships between and among process and product data. The results show interesting similarities and important differences in both process and product characteristics.

  7. Comment on ''Perfect imaging with positive refraction in three dimensions''

    SciTech Connect

    Merlin, R.

    2010-11-15

    Leonhardt and Philbin [Phys. Rev. A 81, 011804(R) (2010)] have recently constructed a mathematical proof that the Maxwell's fish-eye lens provides perfect imaging of electromagnetic waves without negative refraction. In this comment, we argue that the unlimited resolution is an artifact of having introduced an unphysical drain at the position of the geometrical image. The correct solution gives focusing consistent with the standard diffraction limit.

  8. Perfect teleportation and superdense coding with W states

    SciTech Connect

    Agrawal, Pankaj; Pati, Arun

    2006-12-15

    True tripartite entanglement of the state of a system of three qubits can be classified on the basis of stochastic local operations and classical communications. Such states can be classified into two categories: GHZ states and W states. It is known that GHZ states can be used for teleportation and superdense coding, but the prototype W state cannot be. However, we show that there is a class of W states that can be used for perfect teleportation and superdense coding.

  9. Perfect focusing of scalar wave fields in three dimensions.

    PubMed

    Benítez, Pablo; Miñano, Juan C; González, Juan C

    2010-04-12

    A method to design isotropic inhomogeneous refractive index distribution is presented, in which the scalar wave field solutions propagate exactly on an eikonal function (i.e., remaining constant on the Geometrical Optics wavefronts). This method is applied to the design of "dipole lenses", which perfectly focus a scalar wave field emitted from a point source onto a point absorber, in both two and three dimensions. Also, the Maxwell fish-eye lens in two and three dimensions is analysed.

  10. Coherent perfect absorption mediated anomalous reflection and refraction.

    PubMed

    Dutta-Gupta, Shourya; Deshmukh, Rahul; Venu Gopal, Achanta; Martin, Olivier J F; Dutta Gupta, S

    2012-11-01

    We show bending of light on the same side of the normal in a free-standing corrugated metal film under bidirectional illumination. Coherent perfect absorption (CPA) is exploited to suppress the specular zeroth order leading to effective back-bending of light into the "-1" order, while the "+1" order is resonant with the surface mode. The effect is shown to be phase sensitive, yielding CPA and superscattering in the same geometry.

  11. Covariant diagonalization of the perfect fluid stress-energy tensor

    NASA Astrophysics Data System (ADS)

    Garat, Alcides

    2015-02-01

    We introduce new tetrads that manifestly and covariantly diagonalize the stress-energy tensor for a perfect fluid with vorticity at every spacetime point. This new tetrad can be applied to introduce simplification in the analysis of astrophysical relativistic problems where vorticity is present through the Carter-Lichnerowicz equation. We also discuss the origin of inertia in this special case from the standpoint of our new local tetrads.

  12. Tunneling in perfect-fluid (minisuperspace) quantum cosmology

    SciTech Connect

    Brown, J.D. )

    1990-02-15

    A minisuperspace model of general relativity with a positive cosmological constant coupled to a perfect isentropic fluid is presented. The classical equations of motion are solved for a tunneling solution that consists of a Euclidean instanton of the wormhole type, connected to Lorentzian Robertson-Walker universes. The path integral is then defined as a sum over Lorentzian geometries and it is shown that the tunneling solution dominates the semiclassical evaluation of the path integral.

  13. Matching illumination of solid objects.

    PubMed

    Pont, Sylvia C; Koenderink, Jan J

    2007-04-01

    The appearance of objects is determined by their surface reflectance and roughness and by the light field. Conversely, human observers might derive properties of the light field from the appearance of objects. The inverse problem has no unique solution, so perceptual interactions between reflectance, roughness, and lightfield are to be expected. In two separate experiments, we tested whether observers are able to match the illumination of spheres under collimated illumination only (matching of illumination direction) and under more or less diffuse illumination (matching of illumination direction and directedness of the beam). We found that observers are quite able to match collimated illumination directions of two rendered Lambertian spheres. Matching of the collimated beam directions of a Lambertian sphere and that of a real object with arbitrary reflectance and roughness properties resulted in similar results for the azimuthal angle, but in higher variance for the polar angle. Translucent objects and a tennis ball were found to be systematic outliers. If the directedness of the beam was also varied, the direction settings showed larger variance for more diffuse illumination. The directedness settings showed an overall quite large variance and, interestingly, interacted with the polar angle settings. We discuss possible photometrical mechanisms behind these effects.

  14. Aluminum infrared plasmonic perfect absorbers for wavelength selective devices

    NASA Astrophysics Data System (ADS)

    Dao, Thang Duy; Ishii, Satoshi; Chen, Kai; Yokoyama, Takahiro; Nabatame, Toshihide; Nagao, Tadaaki

    2016-09-01

    We demonstrate the development of colloidal lithography technique to fabricate large-area plasmonic perfect absorbers using Al, which is an earth abundant low-cost plasmonic material in contrast to Au and Ag. Using numerical electromagnetic simulations, we optimize the geometrical parameters of Al perfect absorbers (AlPAs) with resonances at desired wavelengths depending on the applications. The fabricated AlPAs exhibit narrowband absorptions with high efficiency up to 98 %. By tuning AlPAs parameters, the resonance of AlPAs can be tuned from the visible to the middle infrared region. The AlPAs can be applied for spectrally selective infrared devices such as selective thermal emitters, selective surface-enhanced vibrational spectroscopy (SEIRA) for molecular sensing and selective IR detectors. In this report, we demonstrate applications of AlPAs for selective thermal emitters and SEIRA. The results obtained here reveal a simple technique to fabricate scalable plasmonic perfect absorbers as well as their potential applications in optoelectronic and photonic devices.

  15. Desperately seeking perfection: Christian discipleship and medical genetics.

    PubMed

    Shuman, Joel

    1999-08-01

    The question of what, if anything, Christian theology as theology might contribute to ethical debates about appropriate uses of medical genetics has often been ignored. The answer is complex, and the author argues it is best characterized by an explanation of the analogous aspirations of the two: both have as their goal the perfection of the human being, both assert that the present disposition of the human body is on a fundamental level more often than not other than it ought to be, and both aspire to transform the present state of the body toward a future state in which present imperfections no longer exist. Given these analogous concerns, it would seem that one of the primary moral contributions that Christianity can make to debates about medical genetics is to ask whether and to what extent the Christian vision of embodied human perfection is compatible with the vision of perfection offered by the sciences pertaining to medical genetics. The author pursues a discussion of this analogy and its implications in this essay.

  16. High-speed cylindrical collapse of two perfect fluids

    NASA Astrophysics Data System (ADS)

    Sharif, M.; Ahmad, Zahid

    2007-09-01

    In this paper, the study of the gravitational collapse of cylindrically distributed two perfect fluid system has been carried out. It is assumed that the collapsing speeds of the two fluids are very large. We explore this condition by using the high-speed approximation scheme. There arise two cases, i.e., bounded and vanishing of the ratios of the pressures with densities of two fluids given by c s , d s . It is shown that the high-speed approximation scheme breaks down by non-zero pressures p 1, p 2 when c s , d s are bounded below by some positive constants. The failure of the high-speed approximation scheme at some particular time of the gravitational collapse suggests the uncertainty on the evolution at and after this time. In the bounded case, the naked singularity formation seems to be impossible for the cylindrical two perfect fluids. For the vanishing case, if a linear equation of state is used, the high-speed collapse does not break down by the effects of the pressures and consequently a naked singularity forms. This work provides the generalisation of the results already given by Nakao and Morisawa (Prog Theor Phys 113:73, 2005) for the perfect fluid.

  17. Thin Perfect Absorbers for Electromagnetic Waves: Theory, Design, and Realizations

    NASA Astrophysics Data System (ADS)

    Ra'di, Y.; Simovski, C. R.; Tretyakov, S. A.

    2015-03-01

    With recent advances in nanophotonics and nanofabrication, considerable progress has been achieved in realizations of thin composite layers designed for full absorption of incident electromagnetic radiation, from microwaves to the visible. If the layer is structured at a subwavelength scale, thin perfect absorbers are usually called "metamaterial absorbers," because these composite structures are designed to emulate some material responses not reachable with any natural material. On the other hand, many thin absorbing composite layers were designed and used already in the time of the introduction of radar technology, predominantly as a means to reduce radar visibility of targets. In view of a wide variety of classical and new topologies of optically thin metamaterial absorbers and plurality of applications, there is a need for a general, conceptual overview of the fundamental mechanisms of full absorption of light or microwave radiation in thin layers. Here, we present such an overview in the form of a general theory of thin perfectly absorbing layers. Possible topologies of perfect metamaterial absorbers are classified based on their fundamental operational principles. For each of the identified classes, we provide design equations and give examples of particular realizations. The concluding section provides a summary and gives an outlook on future developments in this field.

  18. Design and evaluation of robust matched filters for chemical agent detection

    NASA Astrophysics Data System (ADS)

    Niu, Sidi; Golowich, Steven E.; Ingle, Vinay K.; Manolakis, Dimitris G.

    2011-11-01

    Most chemical gas detection algorithms for hyperspectral imaging applications assume a gas with a perfectly known spectral signature. In practice, the chemical signature is either imperfectly measured and/or exhibits spectral variability due to temperature variations and Beer's law. The objective of this work is to explore robust matched filters that take the uncertainty and/or variability of the target signatures into account. We introduce various techniques that control the selectivity of the matched filter and we evaluate their performance in standoff LWIR hyperspectral chemical gas detection applications.

  19. A matching approach to communicate through the plasma sheath surrounding a hypersonic vehicle

    SciTech Connect

    Gao, Xiaotian; Jiang, Binhao

    2015-06-21

    In order to overcome the communication blackout problem suffered by hypersonic vehicles, a matching approach has been proposed for the first time in this paper. It utilizes a double-positive (DPS) material layer surrounding a hypersonic vehicle antenna to match with the plasma sheath enclosing the vehicle. Analytical analysis and numerical results indicate a resonance between the matched layer and the plasma sheath will be formed to mitigate the blackout problem in some conditions. The calculated results present a perfect radiated performance of the antenna, when the match is exactly built between these two layers. The effects of the parameters of the plasma sheath have been researched by numerical methods. Based on these results, the proposed approach is easier to realize and more flexible to the varying radiated conditions in hypersonic flight comparing with other methods.

  20. A matching approach to communicate through the plasma sheath surrounding a hypersonic vehicle

    NASA Astrophysics Data System (ADS)

    Gao, Xiaotian; Jiang, Binhao

    2015-06-01

    In order to overcome the communication blackout problem suffered by hypersonic vehicles, a matching approach has been proposed for the first time in this paper. It utilizes a double-positive (DPS) material layer surrounding a hypersonic vehicle antenna to match with the plasma sheath enclosing the vehicle. Analytical analysis and numerical results indicate a resonance between the matched layer and the plasma sheath will be formed to mitigate the blackout problem in some conditions. The calculated results present a perfect radiated performance of the antenna, when the match is exactly built between these two layers. The effects of the parameters of the plasma sheath have been researched by numerical methods. Based on these results, the proposed approach is easier to realize and more flexible to the varying radiated conditions in hypersonic flight comparing with other methods.

  1. Path similarity skeleton graph matching.

    PubMed

    Bai, Xiang; Latecki, Longin Jan

    2008-07-01

    This paper presents a novel framework to for shape recognition based on object silhouettes. The main idea is to match skeleton graphs by comparing the shortest paths between skeleton endpoints. In contrast to typical tree or graph matching methods, we completely ignore the topological graph structure. Our approach is motivated by the fact that visually similar skeleton graphs may have completely different topological structures. The proposed comparison of shortest paths between endpoints of skeleton graphs yields correct matching results in such cases. The skeletons are pruned by contour partitioning with Discrete Curve Evolution, which implies that the endpoints of skeleton branches correspond to visual parts of the objects. The experimental results demonstrate that our method is able to produce correct results in the presence of articulations, stretching, and occlusion.

  2. Matching optics for Gaussian beams

    NASA Technical Reports Server (NTRS)

    Gunter, William D. (Inventor)

    1991-01-01

    A system of matching optics for Gaussian beams is described. The matching optics system is positioned between a light beam emitter (such as a laser) and the input optics of a second optics system whereby the output from the light beam emitter is converted into an optimum input for the succeeding parts of the second optical system. The matching optics arrangement includes the combination of a light beam emitter, such as a laser with a movable afocal lens pair (telescope) and a single movable lens placed in the laser's output beam. The single movable lens serves as an input to the telescope. If desired, a second lens, which may be fixed, is positioned in the beam before the adjustable lens to serve as an input processor to the movable lens. The system provides the ability to choose waist diameter and position independently and achieve the desired values with two simple adjustments not requiring iteration.

  3. Poor Textural Image Matching Based on Graph Theory

    NASA Astrophysics Data System (ADS)

    Chen, Shiyu; Yuan, Xiuxiao; Yuan, Wei; Cai, Yang

    2016-06-01

    Image matching lies at the heart of photogrammetry and computer vision. For poor textural images, the matching result is affected by low contrast, repetitive patterns, discontinuity or occlusion, few or homogeneous textures. Recently, graph matching became popular for its integration of geometric and radiometric information. Focused on poor textural image matching problem, it is proposed an edge-weight strategy to improve graph matching algorithm. A series of experiments have been conducted including 4 typical landscapes: Forest, desert, farmland, and urban areas. And it is experimentally found that our new algorithm achieves better performance. Compared to SIFT, doubled corresponding points were acquired, and the overall recall rate reached up to 68%, which verifies the feasibility and effectiveness of the algorithm.

  4. Method of stereo matching based on genetic algorithm

    NASA Astrophysics Data System (ADS)

    Lu, Chaohui; An, Ping; Zhang, Zhaoyang

    2003-09-01

    A new stereo matching scheme based on image edge and genetic algorithm (GA) is presented to improve the conventional stereo matching method in this paper. In order to extract robust edge feature for stereo matching, infinite symmetric exponential filter (ISEF) is firstly applied to remove the noise of image, and nonlinear Laplace operator together with local variance of intensity are then used to detect edges. Apart from the detected edge, the polarity of edge pixels is also obtained. As an efficient search method, genetic algorithm is applied to find the best matching pair. For this purpose, some new ideas are developed for applying genetic algorithm to stereo matching. Experimental results show that the proposed methods are effective and can obtain good results.

  5. Understanding the Dreyfus model of skill acquisition to improve ultrasound training for obstetrics and gynaecology trainees.

    PubMed

    Field, Alexander

    2014-05-01

    There have been significant problems in ultrasound training since the introduction of the new postgraduate curriculum for obstetrics and gynaecology. It is therefore important to understand how the skill of ultrasound is acquired in order to be able to improve the training program. Here, the potential application of the Dreyfus model of skill acquisition has been analysed to map the progression from novice to master and the progressions between each stage analysed. Although the Dreyfus model is not a perfect match for ultrasound scanning, it provides us with a theoretical framework on which to underpin educational practice in this field.

  6. Memristor-based pattern matching

    NASA Astrophysics Data System (ADS)

    Klimo, Martin; Such, Ondrej; Skvarek, Ondrej; Fratrik, Milan

    2014-10-01

    Pattern matching is a machine learning area that requires high-performance hardware. It has been hypothesized that massively parallel designs, which avoid von Neumann architecture, could provide a significant performance boost. Such designs can advantageously use memristive switches. This paper discusses a two-stage design that implements the induced ordered weighted average (IOWA) method for pattern matching. We outline the circuit structure and discuss how a functioning circuit can be achieved using metal oxide devices. We describe our simulations of memristive circuits and illustrate their performance on a vowel classification task.

  7. The beauty of match play.

    PubMed

    Clark, Russell D

    2006-06-01

    This study investigated whether higher seeded players have an advanage in the only match play event on the PGA Tour. Analysis showed that the higher seeded won 54% of the time (p=.06); the correlation was .17 (p<.01) between higher seeded players winning and the difference in World Rankings between players. Given professional golfers are at the highest end of the distribution of golf ability, these players are so nearly equal in ability, it is mainly a matter of chance who will win a match play event or who will have the best round on any given day.

  8. 7 CFR 2903.5 - Matching requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., DEPARTMENT OF AGRICULTURE BIODIESEL FUEL EDUCATION PROGRAM General Information § 2903.5 Matching requirements. There are no matching funds requirements for the Biodiesel Fuel Education Program and matching...

  9. 7 CFR 2903.5 - Matching requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., DEPARTMENT OF AGRICULTURE BIODIESEL FUEL EDUCATION PROGRAM General Information § 2903.5 Matching requirements. There are no matching funds requirements for the Biodiesel Fuel Education Program and matching...

  10. 7 CFR 2903.5 - Matching requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., DEPARTMENT OF AGRICULTURE BIODIESEL FUEL EDUCATION PROGRAM General Information § 2903.5 Matching requirements. There are no matching funds requirements for the Biodiesel Fuel Education Program and matching...

  11. 7 CFR 2903.5 - Matching requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., DEPARTMENT OF AGRICULTURE BIODIESEL FUEL EDUCATION PROGRAM General Information § 2903.5 Matching requirements. There are no matching funds requirements for the Biodiesel Fuel Education Program and matching...

  12. 7 CFR 2903.5 - Matching requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., DEPARTMENT OF AGRICULTURE BIODIESEL FUEL EDUCATION PROGRAM General Information § 2903.5 Matching requirements. There are no matching funds requirements for the Biodiesel Fuel Education Program and matching...

  13. Matching theory in natural human environments

    PubMed Central

    McDowell, J. J.

    1988-01-01

    Matching theory is a mathematical account of behavior, many aspects of which have been confirmed in laboratory experiments with nonhuman and human subjects. The theory asserts that behavior is distributed across concurrently available response alternatives in the same proportion that reinforcement is distributed across those alternatives. The theory also asserts that behavior on a single response alternative is a function not only of reinforcement contingent on that behavior, but also of reinforcement contingent on other behaviors and of reinforcement delivered independently of behavior. These assertions constitute important advances in our understanding of the effects of reinforcement on behavior. Evidence from the applied literature suggests that matching theory holds not only in laboratory environments, but also in natural human environments. In addition, the theory has important therapeutic implications. For example, it suggests four new intervention strategies, and it can be used to improve treatment planning and management. Research on matching theory illustrates the progression from laboratory experimentation with nonhuman subjects to therapeutic applications in natural human environments. PMID:22478003

  14. Structural color printing based on plasmonic metasurfaces of perfect light absorption

    DOE PAGES

    Cheng, Fei; Gao, Jie; Luk, Ting S.; ...

    2015-06-05

    Subwavelength structural color filtering and printing technologies employing plasmonic nanostructures have recently been recognized as an important and beneficial complement to the traditional colorant-based pigmentation. However, the color saturation, brightness and incident angle tolerance of structural color printing need to be improved to meet the application requirement. Here we demonstrate a structural color printing method based on plasmonic metasurfaces of perfect light absorption to improve color performances such as saturation and brightness. Thin-layer perfect absorbers with periodic hole arrays are designed at visible frequencies and the absorption peaks are tuned by simply adjusting the hole size and periodicity. Near perfectmore » light absorption with high quality factors are obtained to realize high-resolution, angle-insensitive plasmonic color printing with high color saturation and brightness. Moreover, the fabricated metasurfaces can be protected with a protective coating for ambient use without degrading performances. The demonstrated structural color printing platform offers great potential for applications ranging from security marking to information storage.« less

  15. A free interactive matching program

    SciTech Connect

    J.-F. Ostiguy

    1999-04-16

    For physicists and engineers involved in the design and analysis of beamlines (transfer lines or insertions) the lattice function matching problem is central and can be time-consuming because it involves constrained nonlinear optimization. For such problems convergence can be difficult to obtain in general without expert human intervention. Over the years, powerful codes have been developed to assist beamline designers. The canonical example is MAD (Methodical Accelerator Design) developed at CERN by Christophe Iselin. MAD, through a specialized command language, allows one to solve a wide variety of problems, including matching problems. Although in principle, the MAD command interpreter can be run interactively, in practice the solution of a matching problem involves a sequence of independent trial runs. Unfortunately, but perhaps not surprisingly, there still exists relatively few tools exploiting the resources offered by modern environments to assist lattice designer with this routine and repetitive task. In this paper, we describe a fully interactive lattice matching program, written in C++ and assembled using freely available software components. An important feature of the code is that the evolution of the lattice functions during the nonlinear iterative process can be graphically monitored in real time; the user can dynamically interrupt the iterations at will to introduce new variables, freeze existing ones into their current state and/or modify constraints. The program runs under both UNIX and Windows NT.

  16. Acceptable Ungrammaticality in Sentence Matching

    ERIC Educational Resources Information Center

    Duffield, Nigel; Matsuo, Ayumi; Roberts, Leah

    2007-01-01

    This article presents a new set of experiments using the "sentence-matching paradigm" (Forster, 1979; Freedman and Forster, 1985; see also Bley-Vroman and Masterson, 1989), investigating native speakers' and second language (L2) learners' knowledge of constraints on clitic placement in French. Our purpose is three-fold: (1) to shed more light on…

  17. The Vector Matching Method in Geomagnetic Aiding Navigation.

    PubMed

    Song, Zhongguo; Zhang, Jinsheng; Zhu, Wenqi; Xi, Xiaoli

    2016-07-20

    In this paper, a geomagnetic matching navigation method that utilizes the geomagnetic vector is developed, which can greatly improve the matching probability and positioning precision, even when the geomagnetic entropy information in the matching region is small or the geomagnetic contour line's variety is obscure. The vector iterative closest contour point (VICCP) algorithm that is proposed here has better adaptability with the positioning error characteristics of the inertial navigation system (INS), where the rigid transformation in ordinary ICCP is replaced with affine transformation. In a subsequent step, a geomagnetic vector information fusion algorithm based on Bayesian statistical analysis is introduced into VICCP to improve matching performance further. Simulations based on the actual geomagnetic reference map have been performed for the validation of the proposed algorithm.

  18. The Vector Matching Method in Geomagnetic Aiding Navigation

    PubMed Central

    Song, Zhongguo; Zhang, Jinsheng; Zhu, Wenqi; Xi, Xiaoli

    2016-01-01

    In this paper, a geomagnetic matching navigation method that utilizes the geomagnetic vector is developed, which can greatly improve the matching probability and positioning precision, even when the geomagnetic entropy information in the matching region is small or the geomagnetic contour line’s variety is obscure. The vector iterative closest contour point (VICCP) algorithm that is proposed here has better adaptability with the positioning error characteristics of the inertial navigation system (INS), where the rigid transformation in ordinary ICCP is replaced with affine transformation. In a subsequent step, a geomagnetic vector information fusion algorithm based on Bayesian statistical analysis is introduced into VICCP to improve matching performance further. Simulations based on the actual geomagnetic reference map have been performed for the validation of the proposed algorithm. PMID:27447645

  19. Matching point clouds: limits and possibilities.

    PubMed

    Rudolph, H; Quaas, S; Luthardt, R G

    2002-01-01

    In computer-aided production of fixed dental restorations, the process chain always starts with digitizing, independent of the type of further (data) processing, the material used, and the kind of restoration to be produced. The quality of the digitized data, followed by the influences of further data processing and the production parameters, decisively influence the fitting accuracy of the dental restoration to be fabricated. The accuracy with which individually measured 3D data sets in the form of point clouds can be matched for further processing in one common system of coordinates was the object of the present study. Casts of the maxilla and mandible were digitized in several partial measurements comprising two to three teeth in each case, using an optical three-coordinate measuring system. The individual segments were sequentially aligned to surfaces that were created on the basis of partial point clouds. The mean deviation between surfaces and point clouds was between 1.90 microns and 18.24 microns. The accuracy of the alignment was determined by the RMS (root mean square) error, and was on average 14.2 microns (SD 7 microns) for the maxilla and 17.2 microns (SD 9.4 microns) for the mandible. Combining a larger number of smaller segments did not improve the result, since the errors of the individual registrations are summed in sequential matching. In this study, the errors arising in matching are not negligible and can possibly negatively influence the quality (fitting accuracy) of the restoration produced on the basis of the matched data records.

  20. 78 FR 73195 - Privacy Act of 1974: CMS Computer Matching Program Match No. 2013-01; HHS Computer Matching...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-05

    ... HUMAN SERVICES Centers for Medicare & Medicaid Services Privacy Act of 1974: CMS Computer Matching Program Match No. 2013-01; HHS Computer Matching Program Match No. 1312 AGENCY: Centers for Medicare & Medicaid Services (CMS), Department of Health and Human Services (HHS). ACTION: Notice of Computer...

  1. Probabilistically Perfect Cloning of Two Pure States: Geometric Approach

    NASA Astrophysics Data System (ADS)

    Yerokhin, V.; Shehu, A.; Feldman, E.; Bagan, E.; Bergou, J. A.

    2016-05-01

    We solve the long-standing problem of making n perfect clones from m copies of one of two known pure states with minimum failure probability in the general case where the known states have arbitrary a priori probabilities. The solution emerges from a geometric formulation of the problem. This formulation reveals that cloning converges to state discrimination followed by state preparation as the number of clones goes to infinity. The convergence exhibits a phenomenon analogous to a second-order symmetry-breaking phase transition.

  2. Scattering from thin dielectric straps surrounding a perfectly conducting structure

    NASA Technical Reports Server (NTRS)

    Al-Hekail, Zeyad O.; Gupta, Inder J.; Burnside, Walter D.

    1993-01-01

    Dielectric straps can support very heavy targets and have low backscattering levels, especially at low frequencies (below 8 GHz); thus, they can be used effectively to support targets during backscattered field measurements. In this paper, the scattered fields of nonmagnetic dielectric straps surrounding a perfectly conducting structure are presented, and the computed results are compared with experimental data. Empirical formulas for the strap scattered fields are also given. These formulas are good for general convex structures whose radii of curvature are large compared with the wavelength and are expected to give a reasonable estimate of the true backscattered fields from the dielectric straps when used as a target support structure.

  3. Perfect electromagnetic absorption at one-atom-thick scale

    SciTech Connect

    Li, Sucheng; Duan, Qian; Li, Shuo; Yin, Qiang; Lu, Weixin; Li, Liang; Hou, Bo; Gu, Bangming; Wen, Weijia

    2015-11-02

    We experimentally demonstrate that perfect electromagnetic absorption can be realized in the one-atom thick graphene. Employing coherent illumination in the waveguide system, the absorbance of the unpatterned graphene monolayer is observed to be greater than 94% over the microwave X-band, 7–13 GHz, and to achieve a full absorption, >99% in experiment, at ∼8.3 GHz. In addition, the absorption characteristic manifests equivalently a wide range of incident angle. The experimental results agree very well with the theoretical calculations. Our work accomplishes the broadband, wide-angle, high-performance absorption in the thinnest material with simple configuration.

  4. Hyperbolic Structure for a Simplified Model of Dynamical Perfect Plasticity

    NASA Astrophysics Data System (ADS)

    Babadjian, Jean-François; Mifsud, Clément

    2017-02-01

    This paper is devoted to confronting two different approaches to the problem of dynamical perfect plasticity. Interpreting this model as a constrained boundary value Friedrichs' system enables one to derive admissible hyperbolic boundary conditions. Using variational methods, we show the well-posedness of this problem in a suitable weak measure theoretical setting. Thanks to the property of finite speed propagation, we establish a new regularity result for the solution in short time. Finally, we prove that this variational solution is actually a solution of the hyperbolic formulation in a suitable dissipative/entropic sense, and that a partial converse statement holds under an additional time regularity assumption for the dissipative solutions.

  5. Random Matrix Theory Approach to Chaotic Coherent Perfect Absorbers.

    PubMed

    Li, Huanan; Suwunnarat, Suwun; Fleischmann, Ragnar; Schanz, Holger; Kottos, Tsampikos

    2017-01-27

    We employ random matrix theory in order to investigate coherent perfect absorption (CPA) in lossy systems with complex internal dynamics. The loss strength γ_{CPA} and energy E_{CPA}, for which a CPA occurs, are expressed in terms of the eigenmodes of the isolated cavity-thus carrying over the information about the chaotic nature of the target-and their coupling to a finite number of scattering channels. Our results are tested against numerical calculations using complex networks of resonators and chaotic graphs as CPA cavities.

  6. Seeking perfection: a Kantian look at human genetic engineering.

    PubMed

    Gunderson, Martin

    2007-01-01

    It is tempting to argue that Kantian moral philosophy justifies prohibiting both human germ-line genetic engineering and non-therapeutic genetic engineering because they fail to respect human dignity. There are, however, good reasons for resisting this temptation. In fact, Kant's moral philosophy provides reasons that support genetic engineering-even germ-line and non-therapeutic. This is true of Kant's imperfect duties to seek one's own perfection and the happiness of others. It is also true of the categorical imperative. Kant's moral philosophy does, however, provide limits to justifiable genetic engineering.

  7. Initial rectified attractors for perfect synchronization of chaotic systems

    NASA Astrophysics Data System (ADS)

    Sun, Mingxuan; He, Xiongxiong; Yu, Li

    2005-12-01

    The controlled attractor with initial rectifying action, referred to as initial rectified attractor (IRA) in this Letter, is introduced for the purpose of chaos synchronization. An IRA-based design is presented to make the states of the drive system and the response system synchronized within finite time. The reaching time is shown independent of initial conditions and dynamics of the chaotic systems, and can be pre-specified. With numerical experiments we demonstrate that such perfect synchronization can be achieved for modified Chua's circuit systems and Genesio chaotic systems.

  8. Perfect mirror transport protocol with higher dimensional quantum chains.

    PubMed

    Paz-Silva, Gerardo A; Rebić, Stojan; Twamley, Jason; Duty, Tim

    2009-01-16

    A globally controlled scheme for quantum transport is proposed. The scheme works on a 1D chain of nearest neighbor coupled systems of qudits (finite dimension), or qunats (continuous variable), taking any arbitrary initial quantum state of the chain and producing a final quantum state, which is perfectly spatially mirrored about the midpoint of the chain. As a particular novel application, the method can be used to transport continuous variable quantum states. A physical realization is proposed where it is shown how the quantum states of the microwave fields held in a chain of driven superconducting coplanar waveguides can experience quantum mirror transport when coupled by switchable Cooper pair boxes.

  9. Some symmetry group aspects of a perfect plane plasticity system

    NASA Astrophysics Data System (ADS)

    Senashov, S. I.; Yakhno, A.

    2013-09-01

    In this paper, all the known classical solutions of a plane perfect plasticity system under the Saint Venant-Tresca-von Mises yield criterion are associated with some group of point symmetries. The equations of slip-line families for all solutions are constructed, which allows one to explicitly determine the boundaries of the plastic areas. It is shown how one can determine the compatible velocity solution for known stresses by considering symmetries. Some invariant solutions of velocities for Prandtl stresses are constructed. The mechanical sense of the obtained velocity fields is discussed. To the blessed memory of our teacher D D Ivlev

  10. Alternative Matching Scores to Control Type I Error of the Mantel-Haenszel Procedure for DIF in Dichotomously Scored Items Conforming to 3PL IRT and Nonparametric 4PBCB Models

    ERIC Educational Resources Information Center

    Monahan, Patrick O.; Ankenmann, Robert D.

    2010-01-01

    When the matching score is either less than perfectly reliable or not a sufficient statistic for determining latent proficiency in data conforming to item response theory (IRT) models, Type I error (TIE) inflation may occur for the Mantel-Haenszel (MH) procedure or any differential item functioning (DIF) procedure that matches on summed-item…

  11. The matched-phase coherent multi-frequency matched-field processor

    PubMed

    Orris; Nicholas; Perkins

    2000-05-01

    Coherent multi-frequency matched-field processing is investigated using a matched-phase coherent matched-field processor. Its main difference from previous coherent processors is that the relative phases of the Fourier components contained within the recorded signal are not assumed to be known a priori. Rather they are considered free parameters that can be determined using a global functional minimization algorithm. Additionally, this processor uses only the cross-frequency terms, making it less susceptible to the detrimental effects of ambient noise; in one example, this processor shows a five decibel improvement over a similar coherent processor. Along with its increased sensitivity with respect to the broadcast source levels, this coherent processor exhibits superior range resolution as compared with multi-frequency incoherent processors, due to the cross-frequency interference of the vertical eigenmodes. Within this work we explore the efficacy of the algorithms used to determine the relative phases along with the performance of the matched-phase coherent processor itself, performed within the context of data collected during an event from the SWellEx-96 experiment. Performance comparisons between this processor, an incoherent processor, and another coherent processor are demonstrated using this data set.

  12. Induction Chemotherapy Improved Long-term Outcomes of Patients with Locoregionally Advanced Nasopharyngeal Carcinoma: A Propensity Matched Analysis of 5-year Survival Outcomes in the Era of Intensity-modulated Radiotherapy

    PubMed Central

    Peng, Hao; Chen, Lei; Zhang, Jian; Li, Wen-Fei; Mao, Yan-Ping; Zhang, Yuan; Liu, Li-Zhi; Tian, Li; Lin, Ai-Hua; Sun, Ying; Ma, Jun

    2017-01-01

    Background: The aim of this study is to evaluate the long-term therapeutic gain of induction chemotherapy (IC) in locoregionally advanced nasopharyngeal carcinoma (NPC) in the era of intensity-modulated radiotherapy (IMRT). Methods: Data on 957 patients with stage T1-2N2-3 or T3-4N1-3 NPC treated with IMRT were retrospectively reviewed. Propensity score matching (PSM) method was adopted to balance influence of various covariates. Patient survival between IC and non-IC groups were compared. Results: For the 318 pairs selected from the original 957 patients by PSM, the median follow-up duration was 57.13 months (range, 1.27-78.1 months). The 5-year overall survival (OS), distant metastasis-free survival (DMFS), disease-free survival (DFS) and locoregional relapse-free survival (LRRFS) rates for IC group vs. non-IC group were 87.2% vs. 80.8% (P = 0.023), 88.1% vs. 83.2% (P = 0.071), 80.7% vs. 71.4% (P = 0.011) and 92.1% vs. 86.7% (P = 0.081), respectively. Multivariate analysis identify IC as an independent prognostic factor for OS (HR, 0.595; 95% CI, 0.397-0.891; P = 0.012) and DFS (HR, 0.627; 95% CI, 0.451-0.872; P = 0.006). After excluding the patients not receiving concurrent chemotherapy, IC was found to be an independent prognostic factor for OS (HR, 0.566; 95% CI, 0.368-0.872; P = 0.01), DMFS (HR, 0.580; 95% CI, 0.367-0.916; P = 0.02) and DFS (HR, 0.633; 95% CI, 0.444-0.903; P = 0.012). Conclusions: IC is an effective treatment modality for patients with stage T1-2N2-3 and T3-4N1-3 NPC, and the incorporation of IC with standard CCRT could achieve the best therapeutic gain. PMID:28261337

  13. Photometric invariant stereo matching method.

    PubMed

    Gu, Feifei; Zhao, Hong; Zhou, Xiang; Li, Jinjun; Bu, Penghui; Zhao, Zixin

    2015-12-14

    A robust stereo matching method based on a comprehensive mathematical model for color formation process is proposed to estimate the disparity map of stereo images with noise and photometric variations. The band-pass filter with DoP kernel is firstly used to filter out noise component of the stereo images. Then the log-chromaticity normalization process is applied to eliminate the influence of lightning geometry. All the other factors that may influence the color formation process are removed through the disparity estimation process with a specific matching cost. Performance of the developed method is evaluated by comparing with some up-to-date algorithms. Experimental results are presented to demonstrate the robustness and accuracy of the method.

  14. University Reactor Matching Grants Program

    SciTech Connect

    John Valentine; Farzad Rahnema; Said Abdel-Khalik

    2003-02-14

    During the 2002 Fiscal year, funds from the DOE matching grant program, along with matching funds from the industrial sponsors, have been used to support research in the area of thermal-hydraulics. Both experimental and numerical research projects have been performed. Experimental research focused on two areas: (1) Identification of the root cause mechanism for axial offset anomaly in pressurized water reactors under prototypical reactor conditions, and (2) Fluid dynamic aspects of thin liquid film protection schemes for inertial fusion reactor chambers. Numerical research focused on two areas: (1) Multi-fluid modeling of both two-phase and two-component flows for steam conditioning and mist cooling applications, and (2) Modeling of bounded Rayleigh-Taylor instability with interfacial mass transfer and fluid injection through a porous wall simulating the ''wetted wall'' protection scheme in inertial fusion reactor chambers. Details of activities in these areas are given.

  15. Propensity Score Matching: Retrospective Randomization?

    PubMed

    Jupiter, Daniel C

    Randomized controlled trials are viewed as the optimal study design. In this commentary, we explore the strength of this design and its complexity. We also discuss some situations in which these trials are not possible, or not ethical, or not economical. In such situations, specifically, in retrospective studies, we should make every effort to recapitulate the rigor and strength of the randomized trial. However, we could be faced with an inherent indication bias in such a setting. Thus, we consider the tools available to address that bias. Specifically, we examine matching and introduce and explore a new tool: propensity score matching. This tool allows us to group subjects according to their propensity to be in a particular treatment group and, in so doing, to account for the indication bias.

  16. 32 CFR 806b.50 - Computer matching.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Computer matching. 806b.50 Section 806b.50... PROGRAM Disclosing Records to Third Parties § 806b.50 Computer matching. Computer matching programs... on forms used in applying for benefits. Coordinate computer matching statements on forms with...

  17. 32 CFR 806b.50 - Computer matching.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Computer matching. 806b.50 Section 806b.50... PROGRAM Disclosing Records to Third Parties § 806b.50 Computer matching. Computer matching programs... on forms used in applying for benefits. Coordinate computer matching statements on forms with...

  18. 32 CFR 806b.50 - Computer matching.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Computer matching. 806b.50 Section 806b.50... PROGRAM Disclosing Records to Third Parties § 806b.50 Computer matching. Computer matching programs... on forms used in applying for benefits. Coordinate computer matching statements on forms with...

  19. 32 CFR 806b.50 - Computer matching.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Computer matching. 806b.50 Section 806b.50... PROGRAM Disclosing Records to Third Parties § 806b.50 Computer matching. Computer matching programs... on forms used in applying for benefits. Coordinate computer matching statements on forms with...

  20. DITEC: Technology Matching Tool (TMT)

    DTIC Science & Technology

    2016-08-01

    each sub-capability a numerical priority. (Figure 1) The User Requirement vectors tested were cybersecurity technology vectors, for this...Romero-Mariona, J. 2014. “DITEC (DoD-Centric and Independent Technology Evaluation Capability): A Process for Testing Security.” IEEE Seventh...TECHNICAL REPORT 3021 August 2016 DITEC Technology Matching Tool (TMT) Roger A. Hallman Braulio Coronado . Approved for public

  1. Segment-Based Stereo Matching

    DTIC Science & Technology

    1983-06-01

    N JIIU.J, IMlüliHM — o - SEGMENT-BASED STEREO MATCHING* By o Gerard G. Medioni and Ramakant Nevatia Intelligent Systems Group...industrial robotics. Stereo analysis provides a more direct quantitative depth evaluation than techniques such as shape from shad- ing, and its being...surveillance[Henderson79] and industrial robotics. Proposed solutions for the stereo problem follow a paradigm involving the following steps

  2. Matched witness for multipartite entanglement

    NASA Astrophysics Data System (ADS)

    Chen, Xiao-yu; Jiang, Li-zhen; Xu, Zhu-an

    2017-04-01

    Entanglement criteria for multipartite entangled states are obtained by matching witnesses to multipartite entangled states. The necessary and sufficient criterion of separability for three qubit X states is given as an example to illustrate the procedure of finding a criterion. The result is utilized to obtain the noise tolerance of W state. The necessary and sufficient criteria of three partite separability and full separability for four qubit noisy cluster states, three partite separability for four qubit noisy GHZ states are obtained.

  3. Template Matching on Parallel Architectures,

    DTIC Science & Technology

    1985-07-01

    memory. The processors run asynchronously. Thus according to Hynn’s categories the Butterfl . is a MIMD machine. The processors of the Butterfly are...Generalized Butterfly Architecture This section describes timings for pattern matching on the generalized Butterfl .. Ihe implementations on the Butterfly...these algorithms. Thus the best implementation of the techniques on the generalized Butterfl % are the same as the implementation on the real Butterfly

  4. Matching: its acquisition and generalization.

    PubMed Central

    Crowley, Michael A; Donahoe, John W

    2004-01-01

    Choice typically is studied by exposing organisms to concurrent variable-interval schedules in which not only responses controlled by stimuli on the key are acquired but also switching responses and likely other operants as well. In the present research, discriminated key-pecking responses in pigeons were first acquired using a multiple schedule that minimized the reinforcement of switching operants. Then, choice was assessed during concurrent-probe periods in which pairs of discriminative stimuli were presented concurrently. Upon initial exposure to concurrently presented stimuli, choice approximated exclusive preference for the alternative associated with the higher reinforcement frequency. Concurrent schedules were then implemented that gave increasingly greater opportunities for switching operants to be conditioned. As these operants were acquired, the relation of relative response frequency to relative reinforcement frequency converged toward a matching relation. An account of matching with concurrent schedules is proposed in which responding exclusively to the discriminative stimulus associated with the higher reinforcement frequency declines as the concurrent stimuli become more similar and other operants-notably switching-are acquired and generalize to stimuli from both alternatives. The concerted effect of these processes fosters an approximate matching relation in commonly used concurrent procedures. PMID:15540502

  5. Perfect harmony: A mathematical analysis of four historical tunings

    NASA Astrophysics Data System (ADS)

    Page, Michael F.

    2004-10-01

    In Western music, a musical interval defined by the frequency ratio of two notes is generally considered consonant when the ratio is composed of small integers. Perfect harmony or an ``ideal just scale,'' which has no exact solution, would require the division of an octave into 12 notes, each of which would be used to create six other consonant intervals. The purpose of this study is to analyze four well-known historical tunings to evaluate how well each one approximates perfect harmony. The analysis consists of a general evaluation in which all consonant intervals are given equal weighting and a specific evaluation for three preludes from Bach's ``Well-Tempered Clavier,'' for which intervals are weighted in proportion to the duration of their occurrence. The four tunings, 5-limit just intonation, quarter-comma meantone temperament, well temperament (Werckmeister III), and equal temperament, are evaluated by measures of centrality, dispersion, distance, and dissonance. When all keys and consonant intervals are equally weighted, equal temperament demonstrates the strongest performance across a variety of measures, although it is not always the best tuning. Given C as the starting note for each tuning, equal temperament and well temperament perform strongly for the three ``Well-Tempered Clavier'' preludes examined. .

  6. Perfect harmony: a mathematical analysis of four historical tunings.

    PubMed

    Page, Michael F

    2004-10-01

    In Western music, a musical interval defined by the frequency ratio of two notes is generally considered consonant when the ratio is composed of small integers. Perfect harmony or an "ideal just scale," which has no exact solution, would require the division of an octave into 12 notes, each of which would be used to create six other consonant intervals. The purpose of this study is to analyze four well-known historical tunings to evaluate how well each one approximates perfect harmony. The analysis consists of a general evaluation in which all consonant intervals are given equal weighting and a specific evaluation for three preludes from Bach's "Well-Tempered Clavier," for which intervals are weighted in proportion to the duration of their occurrence. The four tunings, 5-limit just intonation, quarter-comma meantone temperament, well temperament (Werckmeister III), and equal temperament, are evaluated by measures of centrality, dispersion, distance, and dissonance. When all keys and consonant intervals are equally weighted, equal temperament demonstrates the strongest performance across a variety of measures, although it is not always the best tuning. Given C as the starting note for each tuning, equal temperament and well temperament perform strongly for the three "Well-Tempered Clavier" preludes examined.

  7. Optimal control for perfect state transfer in linear quantum memory

    NASA Astrophysics Data System (ADS)

    Nakao, Hideaki; Yamamoto, Naoki

    2017-03-01

    A quantum memory is a system that enables transfer, storage, and retrieval of optical quantum states by ON/OFF switching of the control signal in each stage of the memory. In particular, it is known that, for perfect transfer of a single-photon state, appropriate shaping of the input pulse is required. However, in general, such a desirable pulse shape has a complicated form, which would be hard to generate in practice. In this paper, for a wide class of linear quantum memory systems, we develop a method that reduces the complexity of the input pulse shape of a single photon while maintaining the perfect state transfer. The key idea is twofold; (i) the control signal is allowed to vary continuously in time to introduce an additional degree of freedom, and then (ii) an optimal control problem is formulated to design a simple-formed input pulse and the corresponding control signal. Numerical simulations are conducted for Λ-type atomic media and networked atomic ensembles, to show the effectiveness of the proposed method.

  8. Are immigrants and natives perfect substitutes in production?

    PubMed

    Chiswick, B R; Chiswick, C U; Miller, P W

    1985-01-01

    This article discusses whether immigrant and native labor are perfect substitutes in production when conventional measures of skill and demographic characteristics are held constant. The ratio of immigrant to native labor and the ratio of immigrant to native earnings are studied in 5 major immigrant receiving countries with other variables held constant. Countries included are 1) the US and Britian, where the foreign born are only about 5% to 6% of the adult male labor force; 2) Canada and Australia, where they are about 20% and 30%, respectively; and 3) Israel, where the foreign born are about 3/4 of the Jewish adult male labor force. The relative earnings of adult male immigrants and the adult male native-born sons of immigrants are found to be lower when the labor supply of immigrants is greater. The estimated elasticity of substitution between immigrant and native labor is high, but significantly less than infinity. Workers who are relatively more intensively in the favorable self selection characteristics of immigrants are not perfect substitutes for workers relatively more intensive in country-specific skills. As immigrants increase in the labor force, their relative earnings tend to fall, although the decline is small. Economies have sufficiently flexible markets and develop institutional arrangements to mitigate the relative fail in immigrant earnings as their relative supply increase.

  9. Spherically symmetric Einstein-aether perfect fluid models

    SciTech Connect

    Coley, Alan A.; Latta, Joey; Leon, Genly; Sandin, Patrik E-mail: genly.leon@ucv.cl E-mail: lattaj@mathstat.dal.ca

    2015-12-01

    We investigate spherically symmetric cosmological models in Einstein-aether theory with a tilted (non-comoving) perfect fluid source. We use a 1+3 frame formalism and adopt the comoving aether gauge to derive the evolution equations, which form a well-posed system of first order partial differential equations in two variables. We then introduce normalized variables. The formalism is particularly well-suited for numerical computations and the study of the qualitative properties of the models, which are also solutions of Horava gravity. We study the local stability of the equilibrium points of the resulting dynamical system corresponding to physically realistic inhomogeneous cosmological models and astrophysical objects with values for the parameters which are consistent with current constraints. In particular, we consider dust models in (β−) normalized variables and derive a reduced (closed) evolution system and we obtain the general evolution equations for the spatially homogeneous Kantowski-Sachs models using appropriate bounded normalized variables. We then analyse these models, with special emphasis on the future asymptotic behaviour for different values of the parameters. Finally, we investigate static models for a mixture of a (necessarily non-tilted) perfect fluid with a barotropic equations of state and a scalar field.

  10. Superhydrophobicity in perfection: the outstanding properties of the lotus leaf

    PubMed Central

    Ditsche-Kuru, Petra; Neinhuis, Christoph; Barthlott, Wilhelm

    2011-01-01

    Summary Lotus leaves have become an icon for superhydrophobicity and self-cleaning surfaces, and have led to the concept of the ‘Lotus effect’. Although many other plants have superhydrophobic surfaces with almost similar contact angles, the lotus shows better stability and perfection of its water repellency. Here, we compare the relevant properties such as the micro- and nano-structure, the chemical composition of the waxes and the mechanical properties of lotus with its competitors. It soon becomes obvious that the upper epidermis of the lotus leaf has developed some unrivaled optimizations. The extraordinary shape and the density of the papillae are the basis for the extremely reduced contact area between surface and water drops. The exceptional dense layer of very small epicuticular wax tubules is a result of their unique chemical composition. The mechanical robustness of the papillae and the wax tubules reduce damage and are the basis for the perfection and durability of the water repellency. A reason for the optimization, particularly of the upper side of the lotus leaf, can be deduced from the fact that the stomata are located in the upper epidermis. Here, the impact of rain and contamination is higher than on the lower epidermis. The lotus plant has successfully developed an excellent protection for this delicate epistomatic surface of its leaves. PMID:21977427

  11. The noise factor of receiver coil matching networks in MRI.

    PubMed

    Cao, Xueming; Fischer, Elmar; Gruschke, Oliver; Korvink, Jan G; Hennig, Jürgen; Maunder, Adam M; De Zanche, Nicola; Zaitsev, Maxim

    2017-04-01

    In typical MRI applications the dominant noise sources in the received signal are the sample, the coil loop and the preamplifier. We hypothesize that in some cases (e.g. for very small receiver coils) the matching network noise has to be considered explicitly. Considering the difficulties of direct experimental determinations of the noise factor of matching networks with sufficient accuracy, it is helpful to estimate the noise factor by calculation. A useful formula of the coil matching network is obtained by separating commonly used coil matching network into different stages and calculating their noise factor analytically by a combination of the noise from these stages. A useful formula of the coil matching network is obtained. ADS simulations are performed to verify the theoretical predictions. Thereafter carefully-designed proof-of-concept phantom experiments are carried out to qualitatively confirm the predicted SNR behavior. The matching network noise behavior is further theoretically investigated for a variety of scenarios. It is found that in practice the coil matching network noise can be improved by adjusting the coil open port resonant frequency.

  12. Perfect electromagnetic absorption using graphene and epsilon-near-zero metamaterials

    NASA Astrophysics Data System (ADS)

    Lobet, Michaël; Majerus, Bruno; Henrard, Luc; Lambin, Philippe

    2016-06-01

    The ability of graphene/polymer heterostructures to absorb GHz electromagnetic radiation was recently evidenced both theoretically and experimentally [Batrakov et al., Sci. Rep. 4, 7191 (2014), 10.1038/srep07191 and Lobet et al., Nanotechnology 26, 285702 (2015), 10.1088/0957-4484/26/28/285702]. Maximum absorption was shown to depend solely on refractive indices of incident and emergence media once impedance matching conditions are fulfilled. In this paper, analytical models and numerical simulations are performed for both semi-infinite and finite slab substrate. We evidenced that only three graphene layers separated by a dielectric spacer and an epsilon-near-zero metamaterial as emergence medium allow a perfect absorption for normal incidence. The use of lossless epsilon-near-zero metamaterial prevents radiations to go through the device, because of infinite impedance, and forces them to be totally absorbed in the dissipative medium (graphene). The device is proved to be robust regarding angular incidence up to 45 deg for a semi-infinite epsilon-near-zero metamaterial. The proposed strategy is universal and can be applied to any kind of two-dimensional dissipative materials lying on epsilon-near-zero metamaterial. The proposed absorber does not rely on surface patterning or texturing and hence is more appealing for device applications.

  13. On the gravitational field of a radiating, isothermal perfect gas cloud

    NASA Astrophysics Data System (ADS)

    Campos, L. M. B. C.

    2016-04-01

    The paper considers a static isotropic self-gravitating perfect gas in the presence of thermal radiation. The gravitational field is specified in terms of the radiation and gas pressures. Assuming that the thermodynamic internal energy is small compared with relativistic rest energy, it is shown that the gas pressure satisfies the Lane-Emden equation; the assumption of dominant intrinsic relativistic rest energy is satisfied by the hottest stars. Six-solutions of the Lane-Enden equation are obtained together with the corresponding gravitational fields. The basis for comparison is the singular solution I decaying like the inverse square of the radius, that is the leading term of the asymptotic solution V. Two semi-linear solutions are obtained using as variables nonlinear functions of the gas pressure, leading to nonlinear second-order differential equations that can be linearized; one solution II holds for small radius and leads to zero, finite or infinite central pressure, and the other solution III holds asymptomatically and exhibits pressure oscillations. The singular solution I for large radius is matched to a power series solution IV for small radius leading to a solution valid for all radii. The asymptotic solutions III and V: (i) coincide in their common domain of validity; (ii) can be truncated with good accuracy leading to the solution VI.

  14. Stimulation of vapor nucleation on perfect and imperfect hexagonal lattice surfaces

    NASA Astrophysics Data System (ADS)

    Shevkunov, S. V.

    2008-12-01

    Monte Carlo simulations of water vapor nucleation on a perfect crystal surface and on a surface with defects are performed. Mass exchange with the vapor phase is modeled by using an open ensemble. Cluster-substrate interaction is described in terms of conventional atom-atom potentials. The Hamiltonian of the system includes expressions for electrostatic, polarization, exchange, and dispersion interactions. The Gibbs free energy and work of adsorption are calculated by Monte Carlo simulation in the bicanoĭnical ensemble. The microscopic structure of nuclei is analyzed in terms of pair correlation functions. Periodic boundary conditions are used to simulate an infinite substrate surface. Molecule-substrate and molecule-molecule long-range electrostatic interactions are calculated by summing the Fourier harmonics of the electrostatic potential. Dispersion interactions are calculated by direct summation over layers of unit cells. Nucleation on a surface with matching structure follows a layer-by-layer mechanism. The work of adsorption per molecule of a monolayer on the substrate surface has a maximum as a function of nucleus size. The steady rate of nucleation of islands of supercritical size is evaluated. The work of adsorption per molecule for layer-by-layer film growth is an oscillating function of cluster size. As a function of layer number, it has a minimum depending on the vapor pressure. The electric field generated by a microscopic surface protrusion destroys the layered structure of the condensate and eliminates free-energy nucleation barriers. However, point lattice defects do not stimulate explosive nucleation.

  15. Cost-effective description of strong correlation: Efficient implementations of the perfect quadruples and perfect hextuples models

    NASA Astrophysics Data System (ADS)

    Lehtola, Susi; Parkhill, John; Head-Gordon, Martin

    2016-10-01

    Novel implementations based on dense tensor storage are presented for the singlet-reference perfect quadruples (PQ) [J. A. Parkhill et al., J. Chem. Phys. 130, 084101 (2009)] and perfect hextuples (PH) [J. A. Parkhill and M. Head-Gordon, J. Chem. Phys. 133, 024103 (2010)] models. The methods are obtained as block decompositions of conventional coupled-cluster theory that are exact for four electrons in four orbitals (PQ) and six electrons in six orbitals (PH), but that can also be applied to much larger systems. PQ and PH have storage requirements that scale as the square, and as the cube of the number of active electrons, respectively, and exhibit quartic scaling of the computational effort for large systems. Applications of the new implementations are presented for full-valence calculations on linear polyenes (CnHn+2), which highlight the excellent computational scaling of the present implementations that can routinely handle active spaces of hundreds of electrons. The accuracy of the models is studied in the π space of the polyenes, in hydrogen chains (H50), and in the π space of polyacene molecules. In all cases, the results compare favorably to density matrix renormalization group values. With the novel implementation of PQ, active spaces of 140 electrons in 140 orbitals can be solved in a matter of minutes on a single core workstation, and the relatively low polynomial scaling means that very large systems are also accessible using parallel computing.

  16. Cauchy based matched filter for retinal vessels detection.

    PubMed

    Zolfagharnasab, Hooshiar; Naghsh-Nilchi, Ahmad Reza

    2014-01-01

    In this paper, a novel matched filter based on a new kernel function with Cauchy distribution is introduced to improve the accuracy of the automatic retinal vessel detection compared with other available matched filter-based methods, most notably, the methods built on Gaussian distribution function. Several experiments are conducted to pick the best values of the parameters for the new designed filter, including both Cauchy function parameters as well as the matched filter parameters such as the threshold value. Moreover, the thresholding phase is enhanced with a two-step procedure. Experimental results employed on DRIVE retinal images database confirms that the proposed method has higher accuracy compared with other available matched filter-based methods.

  17. Two topics in nonperturbative lattice field theories: The U(1) quantum link model and perfect actions for scalar theories

    NASA Astrophysics Data System (ADS)

    Tsapalis, Antonios S.

    This thesis deals with two topics in lattice field theories. In the first part we discuss aspects of renormalization group flow and non-perturbative improvement of actions for scalar theories regularized on a lattice. We construct a perfect action, an action which is free of lattice artifacts, for a given theory. It is shown how a good approximation to the perfect action-referred to as classically perfect-can be constructed based on a well-defined blocking scheme for the O(3) non-linear σ-model. We study the O(N) non- linear σ-model in the large-N limit and derive analytically its perfect action. This action is applied to the O(3) model on a square lattice. The Wolff cluster algorithm is used to simulate numerically the system. We perform scaling tests and discuss the scaling properties of the large- N inspired perfect action as opposed to the standard and the classically perfect action. In the second part we present a new formulation for a quantum field theory with Abelian gauge symmetry. A Hamiltonian is constructed on a four-dimensional Euclidean space-time lattice which is invariant under local transformations. The model is formulated as a 5- dimensional path integral of discrete variables. We argue that dimensional reduction will allow us to study the behavior of the standard compact U(1) gauge theory in 4-d. Based on the idea of the loop- cluster algorithm for quantum spins, we present the construction of a flux-cluster algorithm for the U(1) quantum link model for the spin-1/2 quantization of the electric flux. It is shown how improved estimators for Wilson loop expectation values can be defined. This is important because the Wilson loops are traditionally used to identify confining and Coulomb phases in gauge theories. Our study indicates that the spin-1/2 U(1) quantum link model is strongly coupled for all bare coupling values we examined. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

  18. Chemoradiation for Advanced Head and Neck Cancer: Potential for Improving Results to Match Those of Current Treatment Modalities for Early-Stage Tumors-Long-Term Results of Hyperfractionated Chemoradiation With Carbogen Breathing and Anemia Correction With Erythropoietin

    SciTech Connect

    Villar, Alfonso Martinez, Jose Carlos; Serdio, Jose Luis de

    2008-04-01

    Purpose: To attempt to improve results of chemoradiation for head and neck cancer. Methods and Materials: From March 1996 to April 2007, 98 patients with head and neck cancer (15 Stage III and 83 Stage IV) were treated with a twice-daily hyperfractionated schedule. Eleven patients presented with N0, 11 with N1, 13 with N2A, 17 with N2B, 24 with N2C, and 22 with N3. Each fraction of treatment consisted of 5 mg/m{sup 2} of carboplatin plus 115 cGy with carbogen breathing. Treatment was given 5 days per week up to total doses of 350 mg/m{sup 2} of carboplatin plus 8050 cGy in 7 weeks. Anemia was corrected with erythropoietin. Results: Ninety-six patients tolerated the treatment as scheduled. All patients tolerated the planned radiation dose. Local toxicity remained at the level expected with irradiation alone. Chemotherapy toxicity was moderate. Ninety-seven complete responses were achieved. After 11 years of follow-up (median, 81 months), actuarial locoregional control, cause-specific survival, overall survival, and nodal control rates at 5 and 10 years were, respectively, 83% and 83%, 68% and 68%, 57% and 55%, and 100% and 100%. Median follow-up of disease-free survivors was 80 months. No significant differences in survival were observed between the different subsites or between the pretreatment node status groups (N0 vs. N+, N0 vs. N1, N0 vs. N2A, N0 vs. N2B, N0 vs. N2C, and N0 vs. N3). Conclusions: Improving results of chemoradiation for advanced head and neck cancer up to the level obtained with current treatments for early-stage tumors is a potentially reachable goal.

  19. Approaching perfection in the manufacturing of silicon immersion gratings

    NASA Astrophysics Data System (ADS)

    Kidder, Benjamin T.; Brooks, Cynthia B.; Grigas, Michelle M.; Jaffe, Daniel T.

    2016-07-01

    Silicon immersion gratings make near-IR spectrographs compact and allow them to have continuous wavelength coverage over a large bandwidth. We have produced an exceptional silicon immersion grating that approaches optical perfection in terms of surface error. This grating has a peak-to-valley error of 79 nm over a 25 mm beam, which exceeds the 85 nm requirement to have λ/4 peak-to-valley error at the shortest wavelength where silicon immersion gratings can be used. In order to reduce the level of large-scale errors we have honed our contact printing method by optimizing our UV exposure system, introducing additional process checks and inspections and carefully evaluating large-scale errors in the gratings produced.

  20. Option pricing and perfect hedging on correlated stocks

    NASA Astrophysics Data System (ADS)

    Perelló, Josep; Masoliver, Jaume

    2003-12-01

    We develop a theory for option pricing with perfect hedging in an inefficient market model where the underlying price variations are autocorrelated over a time τ⩾0. This is accomplished by assuming that the underlying noise in the system is derived by an Ornstein-Uhlenbeck, rather than from a Wiener process. With a modified portfolio consisting in calls, secondary calls and bonds we achieve a riskless strategy which results in a closed and exact expression for the European call price which is always lower than Black-Scholes price. We obtain the same price and a modified delta hedging if we start from an effective one-dimensional market model. We compare these strategies and study the sensitivity of the call price to several parameters where the correlation effects are also observed.

  1. Coherent perfect absorption in one-sided reflectionless media

    PubMed Central

    Wu, Jin-Hui; Artoni, M.; La Rocca, G. C.

    2016-01-01

    In optical experiments one-sided reflectionless (ORL) and coherent perfect absorption (CPA) are unusual scattering properties yet fascinating for their fundamental aspects and for their practical interest. Although these two concepts have so far remained separated from each other, we prove that the two phenomena are indeed strictly connected. We show that a CPA–ORL connection exists between pairs of points lying along lines close to each other in the 3D space-parameters of a realistic lossy atomic photonic crystal. The connection is expected to be a generic feature of wave scattering in non-Hermitian optical media encompassing, as a particular case, wave scattering in parity-time (PT) symmetric media. PMID:27759020

  2. No-signaling, perfect bipartite dichotomic correlations and local randomness

    SciTech Connect

    Seevinck, M. P.

    2011-03-28

    The no-signaling constraint on bi-partite correlations is reviewed. It is shown that in order to obtain non-trivial Bell-type inequalities that discern no-signaling correlations from more general ones, one must go beyond considering expectation values of products of observables only. A new set of nontrivial no-signaling inequalities is derived which have a remarkably close resemblance to the CHSH inequality, yet are fundamentally different. A set of inequalities by Roy and Singh and Avis et al., which is claimed to be useful for discerning no-signaling correlations, is shown to be trivially satisfied by any correlation whatsoever. Finally, using the set of newly derived no-signaling inequalities a result with potential cryptographic consequences is proven: if different parties use identical devices, then, once they have perfect correlations at spacelike separation between dichotomic observables, they know that because of no-signaling the local marginals cannot but be completely random.

  3. Semiconductor meta-surface based perfect light absorber.

    PubMed

    Liu, Guiqiang; Nie, Yiyou; Fu, Guolan; Liu, Xiaoshan; Liu, Yi; Tang, Li; Liu, Zhengqi

    2017-04-21

    We numerically proposed and demonstrated a semiconductor meta-surface light absorber, which consists of a silicon patches array on a silicon thin-film and an opaque silver substrate. The Mie resonances of the silicon patches and the fundamental cavity mode of the ultra-thin silicon film couple strongly to the incident optical field, leading to a multi-band perfect absorption. The maximal absorption is above 99.5% and the absorption is polarization-independent. Moreover, the absorption behavior is scalable in the frequency region via tuning the structural parameters. These features hold the absorber platform with wide applications in optoelectronics such as hot-electron excitation and photo-detection.

  4. Transformation media producing quasi-perfect isotropic emission.

    PubMed

    Tichit, Paul-Henri; Burokur, Shah Nawaz; de Lustrac, André

    2011-10-10

    Using the idea of wave manipulation via transformation optics, we propose a way to create a quasi-perfect isotropic emission from a directional one. The manipulation is enabled by composite metamaterials that correspond to a space stretching around the source. It is shown that the directive radiation of a plane source larger than the operating wavelength can be transformed into an isotropic one by modifying the electromagnetic properties of the space around it. A set of parameters allowing practical realization of the proposed device is defined. Numerical simulations using Finite Element Method (FEM) are performed to illustrate the proposed coordinate transformation. This idea, which consists in strongly reducing the apparent size of a radiating source, can find various applications in novel antenna design techniques.

  5. On the locally rotationally symmetric Einstein-Maxwell perfect fluid

    NASA Astrophysics Data System (ADS)

    Pugliese, D.; Valiente Kroon, J. A.

    2016-06-01

    We examine the stability of Einstein-Maxwell perfect fluid configurations with a privileged radial direction by means of a 1+1+2-tetrad formalism. We use this formalism to cast in a quasilinear symmetric hyperbolic form the equations describing the evolution of the system. This hyperbolic reduction is used to discuss the stability of linear perturbations in some special cases. By restricting the analysis to isotropic fluid configurations, we assume a constant electrical conductivity coefficient for the fluid. As a result of this analysis we provide a complete classification and characterization of various stable and unstable configurations. We find, in particular, that in many cases the stability conditions are strongly determined by the constitutive equations and the electric conductivity. A threshold for the emergence of the instability appears in both contracting and expanding systems.

  6. A Perfect Electromagnetic Cavity: High Quality Factor in Subwavelength Dimensions

    NASA Astrophysics Data System (ADS)

    Ginis, Vincent; Tassin, Philippe; Soukoulis, Costas M.; Veretennicoff, Irina

    2010-03-01

    Transformation optics has recently provided a new way to look at the interaction between light and matter. It uses the analogy between the macroscopic Maxwell's equations in complex dielectrics and the free-space Maxwell's equations on the background of an arbitrary metric to exploit the full potential of metamaterials, of which the most exciting examples are invisibility cloaks. In this contribution, we want to show how transformation optics can be applied to design a cavity with extraordinary properties. We have demonstrated theoretically the existence of eigenmodes whose wavelength is much larger than the characteristic dimensions of the cavity. Furthermore, our design avoids the bending losses observed in traditional microcavities, so that the quality factor is only limited by intrinsic absorption of the materials. Such a ``perfect cavity'' may be interesting for applications involving optical data storage or quantum optics, where it can be used to control the rate of spontaneous emission through the Purcell effect.

  7. Symmetric quantum fully homomorphic encryption with perfect security

    NASA Astrophysics Data System (ADS)

    Liang, Min

    2013-12-01

    Suppose some data have been encrypted, can you compute with the data without decrypting them? This problem has been studied as homomorphic encryption and blind computing. We consider this problem in the context of quantum information processing, and present the definitions of quantum homomorphic encryption (QHE) and quantum fully homomorphic encryption (QFHE). Then, based on quantum one-time pad (QOTP), we construct a symmetric QFHE scheme, where the evaluate algorithm depends on the secret key. This scheme permits any unitary transformation on any -qubit state that has been encrypted. Compared with classical homomorphic encryption, the QFHE scheme has perfect security. Finally, we also construct a QOTP-based symmetric QHE scheme, where the evaluate algorithm is independent of the secret key.

  8. Expanding perfect fluid generalizations of the C metric

    SciTech Connect

    Wylleman, Lode; Beke, David

    2010-05-15

    Petrov type D gravitational fields, generated by a perfect fluid with spatially homogeneous energy density and with flow lines which form a nonshearing and nonrotating timelike congruence, are reexamined. It turns out that the anisotropic such spacetimes, which comprise the vacuum C metric as a limit case, can have nonzero expansion, contrary to the conclusion in the original investigation by Barnes [A. Barnes, Gen. Relativ. Gravit. 4, 105 (1973).]. Apart from the static members, this class consists of cosmological models with precisely one symmetry. The general line element is constructed and some important properties are discussed. It is also shown that purely electric Petrov type D vacuum spacetimes admit shear-free normal timelike congruences everywhere, even in the nonstatic regions. This result incited to deduce intrinsic, easily testable criteria regarding shear-free normality and staticity of Petrov type D spacetimes in general, which are added in an appendix.

  9. Perfect spin filtering effect in ultrasmall helical zigzag graphene nanoribbons

    NASA Astrophysics Data System (ADS)

    Zhang, Zi-Yue

    2017-02-01

    The spin-polarized transport properties of helical zigzag graphene nanoribbons (ZGNRs) are investigated by first-principles calculations. It is found that although all helical ZGNRs have similar density of states and edge states, they show obviously different transport characteristics depending on the curling manners. ZGNRs curled along zigzag orientation exhibit perfect spin filtering effect with a large spin-split gap near the Fermi level, while ZGNRs curled along armchair orientation behave as conventional conductors for both two spin channels. The spin filtering effect will be weakened with the increase of either ribbon width or curling diameter. The results suggest that ultrasmall helical ZGNRs have important potential applications in spintronics and flexible electronics.

  10. Thermally induced nonlinear optical absorption in metamaterial perfect absorbers

    SciTech Connect

    Guddala, Sriram Kumar, Raghwendra; Ramakrishna, S. Anantha

    2015-03-16

    A metamaterial perfect absorber consisting of a tri-layer (Al/ZnS/Al) metal-dielectric-metal system with top aluminium nano-disks was fabricated by laser-interference lithography and lift-off processing. The metamaterial absorber had peak resonant absorbance at 1090 nm and showed nonlinear absorption for 600ps laser pulses at 1064 nm wavelength. A nonlinear saturation of reflectance was measured to be dependent on the average laser power incident and not the peak laser intensity. The nonlinear behaviour is shown to arise from the heating due to the absorbed radiation and photo-thermal changes in the dielectric properties of aluminium. The metamaterial absorber is seen to be damage resistant at large laser intensities of 25 MW/cm{sup 2}.

  11. Acoustic Coherent Perfect Absorbers as Sensitive Null Detectors

    PubMed Central

    Meng, Chong; Zhang, Xiaonan; Tang, Suet To; Yang, Min; Yang, Zhiyu

    2017-01-01

    We report the experimental realization of acoustic coherent perfect absorption (CPA) of four symmetric scatterers of very different structures. The only conditions necessary for these scatterers to exhibit CPA are that both the reflection and transmission amplitudes of the scatterers are 0.5 under one incident wave, and there are two collinear and counter-propagating incident waves with appropriate relative amplitude and phase. Nearly 1000 times in the modulation of output power has been demonstrated by changing the relative phase of the incident waves over 180°. We further demonstrate that these scatterers could potentially be sensitive devices to detect the small differences between two nearly equal incident waves. A 27% change in the strength of the scattering wave has been demonstrated for every degree of phase deviation from the optimum condition between the incident waves. PMID:28262716

  12. Acoustic Coherent Perfect Absorbers as Sensitive Null Detectors

    NASA Astrophysics Data System (ADS)

    Meng, Chong; Zhang, Xiaonan; Tang, Suet To; Yang, Min; Yang, Zhiyu

    2017-03-01

    We report the experimental realization of acoustic coherent perfect absorption (CPA) of four symmetric scatterers of very different structures. The only conditions necessary for these scatterers to exhibit CPA are that both the reflection and transmission amplitudes of the scatterers are 0.5 under one incident wave, and there are two collinear and counter-propagating incident waves with appropriate relative amplitude and phase. Nearly 1000 times in the modulation of output power has been demonstrated by changing the relative phase of the incident waves over 180°. We further demonstrate that these scatterers could potentially be sensitive devices to detect the small differences between two nearly equal incident waves. A 27% change in the strength of the scattering wave has been demonstrated for every degree of phase deviation from the optimum condition between the incident waves.

  13. Thermally induced nonlinear optical absorption in metamaterial perfect absorbers

    NASA Astrophysics Data System (ADS)

    Guddala, Sriram; Kumar, Raghwendra; Ramakrishna, S. Anantha

    2015-03-01

    A metamaterial perfect absorber consisting of a tri-layer (Al/ZnS/Al) metal-dielectric-metal system with top aluminium nano-disks was fabricated by laser-interference lithography and lift-off processing. The metamaterial absorber had peak resonant absorbance at 1090 nm and showed nonlinear absorption for 600ps laser pulses at 1064 nm wavelength. A nonlinear saturation of reflectance was measured to be dependent on the average laser power incident and not the peak laser intensity. The nonlinear behaviour is shown to arise from the heating due to the absorbed radiation and photo-thermal changes in the dielectric properties of aluminium. The metamaterial absorber is seen to be damage resistant at large laser intensities of 25 MW/cm2.

  14. Perfect mixing of immiscible macromolecules at fluid interfaces

    NASA Astrophysics Data System (ADS)

    Sheiko, Sergei; Matyjaszewski, Krzysztof; Tsukruk, Vladimir; Carrillo, Jan-Michael; Rubinstein, Michael; Dobrynin, Andrey; Zhou, Jing

    2014-03-01

    Macromolecules typically phase separate unless their shapes and chemical compositions are tailored to explicitly drive mixing. But now our research has shown that physical constraints can drive spontaneous mixing of chemically different species. We have obtained long-range 2D arrays of perfectly mixed macromolecules having a variety of molecular architectures and chemistries, including linear chains, block-copolymer stars, and bottlebrush copolymers with hydrophobic, hydrophilic, and lipophobic chemical compositions. This is achieved by entropy-driven enhancement of steric repulsion between macromolecules anchored on a substrate. By monitoring the kinetics of mixing, we have proved that molecular intercalation is an equilibrium state. The array spacing is controlled by the length of the brush side chains. This entropic templating strategy opens new ways for generating patterns on sub-100 nm length scales with potential application in lithography, directed self-assembly, and biomedical assays. Financial support from the National Science Foundation DMR-0906985, DMR-1004576, DMR-1122483, and DMR-0907515.

  15. Acoustic Coherent Perfect Absorbers as Sensitive Null Detectors.

    PubMed

    Meng, Chong; Zhang, Xiaonan; Tang, Suet To; Yang, Min; Yang, Zhiyu

    2017-03-06

    We report the experimental realization of acoustic coherent perfect absorption (CPA) of four symmetric scatterers of very different structures. The only conditions necessary for these scatterers to exhibit CPA are that both the reflection and transmission amplitudes of the scatterers are 0.5 under one incident wave, and there are two collinear and counter-propagating incident waves with appropriate relative amplitude and phase. Nearly 1000 times in the modulation of output power has been demonstrated by changing the relative phase of the incident waves over 180°. We further demonstrate that these scatterers could potentially be sensitive devices to detect the small differences between two nearly equal incident waves. A 27% change in the strength of the scattering wave has been demonstrated for every degree of phase deviation from the optimum condition between the incident waves.

  16. How perfect can a gluon plasma be in perturbative QCD?

    SciTech Connect

    Chen, Jiunn-Wei; Deng Jian; Dong Hui; Wang Qun

    2011-02-01

    The shear viscosity to entropy density ratio, {eta}/s, characterizes how perfect a fluid is. We calculate the leading order {eta}/s of a gluon plasma in perturbation using the kinetic theory. The leading order contribution only involves the elastic gg{r_reversible}gg (22) process and the inelastic gg{r_reversible}ggg (23) process. The hard-thermal-loop (HTL) treatment is used for the 22 matrix element, while the exact matrix element in vacuum is supplemented by the gluon Debye mass insertion for the 23 process. Also, the asymptotic mass is used for the external gluons in the kinetic theory. The errors from not implementing HTL and the Landau-Pomeranchuk-Migdal effect in the 23 process, and from the uncalculated higher order corrections, are estimated. Our result smoothly connects the two different approximations used by Arnold, Moore, and Yaffe (AMY) and Xu and Greiner (XG). At small {alpha}{sub s} ({alpha}{sub s}<<1), our result is closer to AMY's collinear result while at larger {alpha}{sub s} the finite angle noncollinear configurations become more important and our result is closer to XG's soft bremsstrahlung result. In the region where perturbation is reliable ({alpha}{sub s} < or approx. 0.1), we find no indication that the proposed perfect fluid limit {eta}/s{approx_equal}1/(4{pi}) can be achieved by perturbative QCD alone. Whether this can be achieve for {alpha}{sub s} > or approx. 0.1 is still an open question.

  17. A perfect storm in interventional pain management: regulated, but unbalanced.

    PubMed

    Benyamin, Ramsin M; Datta, Sukdeb; Falco, Frank J E

    2010-01-01

    Interventional pain management now stands at the crossroads at what is described as "the perfect storm." The confluence of several factors has led to devastating results for interventional pain management. This article seeks to provide a perspective to various issues producing conditions conducive to creating a "perfect storm" such as use and abuse of interventional pain management techniques, and in the same context, use and abuse of various non-interventional techniques. The rapid increase in opioid drug prescribing, costs to health care, large increases in death rates, and random and rampant drug testing, can also lead to increases in health care utilization. Other important aspects that are seldom discussed include medico-legal and ethical perspectives of individual and professional societal opinions and the interpretation of diagnostic accuracy of controlled diagnostic blocks. The aim of this article is to discuss the impact of several factors on interventional pain management and overuse, abuse, waste, and fraud; inappropriate application without evidence-based literature support (sometimes leading to selective use or non-use of randomized or observational studies for proving biased viewpoints - post priori rather than a priori), and issues related to multiple professional societies having their own agendas to push rather than promulgating the science of interventional pain management. This perspective is based on a review of articles published in this issue of Pain Physician, information in the public domain, and other relevant articles. Based on the results of this review, various issues of relevance to modern interventional pain management are discussed and the viewpoints of several experts debated. In conclusion, supporters of interventional pain management disagree on multiple aspects for various reasons while detractors claim that interventional pain management should not exist as a speciality. Issues to be addressed include appropriate use of evidence

  18. Perfect fluid tori orbiting Kehagias-Sfetsos naked singularities

    NASA Astrophysics Data System (ADS)

    Stuchlík, Z.; Pugliese, D.; Schee, J.; Kučáková, H.

    2015-09-01

    We construct perfect fluid tori in the field of the Kehagias-Sfetsos (K-S) naked singularities. These are spherically symmetric vacuum solutions of the modified Hořava quantum gravity, characterized by a dimensionless parameter ω M^2, combining the gravitational mass parameter M of the spacetime with the Hořava parameter ω reflecting the role of the quantum corrections. In dependence on the value of ω M^2, the K-S naked singularities demonstrate a variety of qualitatively different behavior of their circular geodesics that is fully reflected in the properties of the toroidal structures, demonstrating clear distinction to the properties of the torii in the Schwarzschild spacetimes. In all of the K-S naked singularity spacetimes the tori are located above an "antigravity" sphere where matter can stay in a stable equilibrium position, which is relevant for the stability of the orbiting fluid toroidal accretion structures. The signature of the K-S naked singularity is given by the properties of marginally stable tori orbiting with the uniform distribution of the specific angular momentum of the fluid, l= const. In the K-S naked singularity spacetimes with ω M^2 > 0.2811, doubled tori with the same l= const can exist; mass transfer between the outer torus and the inner one is possible under appropriate conditions, while only outflow to the outer space is allowed in complementary conditions. In the K-S spacetimes with ω M^2 < 0.2811, accretion from cusped perfect fluid tori is not possible due to the non-existence of unstable circular geodesics.

  19. On the Conditional Matching of Fractal Networks

    NASA Astrophysics Data System (ADS)

    Wang, Yanchun; Sun, Weigang; Zhang, Jingyuan; Qin, Sen

    2016-12-01

    In this paper, we propose a new matching (called a conditional matching), where the condition refers to the matching of the new constructed network which includes all the nodes in the original network. We then enumerate the conditional matchings of the new network and prove that the number of conditional matchings is just the product of degree sequences of the original network. We choose two families of fractal networks to show our obtained results, including the pseudofractal network and Cayley tree. Finally, we calculate the entropy of the conditional matchings on the considered networks and see that the entropy of Cayley tree is smaller than that of the pseudofractal network.

  20. Phenotype–environment matching in sand fleas

    PubMed Central

    Stevens, Martin; Broderick, Annette C.; Godley, Brendan J.; Lown, Alice E.; Troscianko, Jolyon; Weber, Nicola; Weber, Sam B.

    2015-01-01

    Camouflage is perhaps the most widespread anti-predator strategy in nature, found in numerous animal groups. A long-standing prediction is that individuals should have camouflage tuned to the visual backgrounds where they live. However, while several studies have demonstrated phenotype–environment associations, few have directly shown that this confers an improvement in camouflage, particularly with respect to predator vision. Here, we show that an intertidal crustacean, the sand flea (Hippa testudinaria), has coloration tuned to the different substrates on which it occurs when viewed by potential avian predators. Individual sand fleas from a small, oceanic island (Ascension) matched the colour and luminance of their own beaches more closely than neighbouring beaches to a model of avian vision. Based on past work, this phenotype–environment matching is likely to be driven through ontogenetic changes rather than genetic adaptation. Our work provides some of the first direct evidence that animal coloration is tuned to provide camouflage to prospective predators against a range of visual backgrounds, in a population of animals occurring over a small geographical range. PMID:26268993

  1. Phenotype-environment matching in sand fleas.

    PubMed

    Stevens, Martin; Broderick, Annette C; Godley, Brendan J; Lown, Alice E; Troscianko, Jolyon; Weber, Nicola; Weber, Sam B

    2015-08-01

    Camouflage is perhaps the most widespread anti-predator strategy in nature, found in numerous animal groups. A long-standing prediction is that individuals should have camouflage tuned to the visual backgrounds where they live. However, while several studies have demonstrated phenotype-environment associations, few have directly shown that this confers an improvement in camouflage, particularly with respect to predator vision. Here, we show that an intertidal crustacean, the sand flea (Hippa testudinaria), has coloration tuned to the different substrates on which it occurs when viewed by potential avian predators. Individual sand fleas from a small, oceanic island (Ascension) matched the colour and luminance of their own beaches more closely than neighbouring beaches to a model of avian vision. Based on past work, this phenotype-environment matching is likely to be driven through ontogenetic changes rather than genetic adaptation. Our work provides some of the first direct evidence that animal coloration is tuned to provide camouflage to prospective predators against a range of visual backgrounds, in a population of animals occurring over a small geographical range.

  2. Self-limited self-perfection by liquefaction for sub-20 nm trench/line fabrication.

    PubMed

    Liang, Yixing; Murphy, Patrick; Li, Wen-Di; Chou, Stephen Y

    2009-11-18

    We proposed and demonstrated a new approach to pressed self-perfection by liquefaction (P-SPEL), where a layer of SiO2 is used as a stopper on one sidewall of gratings, to self-limit the final trench width in P-SPEL to a preset stopper layer thickness, allowing a precise control of the final trench width without the need to control any pressing parameters such as pressure, temperature and the gap between the pressing plate and the substrate. We achieved 20 nm wide trenches from a 90 nm original width, reducing the original trench by 450%. We also observed improvement in the trench width uniformity. Using the fabricated resist trenches as templates, 20 nm metal lines were achieved by lift-off.

  3. The landscape of DNA methylation amid a perfect storm of autism aetiologies

    PubMed Central

    Ciernia, Annie Vogel; LaSalle, Janine

    2016-01-01

    Increasing evidence points to a complex interplay between genes and the environment in autism spectrum disorder (ASD), including rare de novo mutations in chromatin genes such as methyl-CpG binding protein 2 (MECP2) in Rett syndrome. Epigenetic mechanisms such as DNA methylation act at this interface, reflecting the plasticity in metabolic and neurodevelopmentally regulated gene pathways. Genome-wide studies of gene sequences, gene pathways and DNA methylation are providing valuable mechanistic insights into ASD. The dynamic developmental landscape of DNA methylation is vulnerable to numerous genetic and environmental insults: therefore, understanding pathways that are central to this ‘perfect storm’ will be crucial to improving the diagnosis and treatment of ASD. PMID:27150399

  4. The formulation and performance of a perturbative correction to the perfect quadruples model

    NASA Astrophysics Data System (ADS)

    Parkhill, John A.; Azar, Julian; Head-Gordon, Martin

    2011-04-01

    A recently published alternative hierarchy of coupled-cluster approximations is reformulated as a perturbative correction. A single variant, a model for the total electronic energy based on the perfect quadruples model, is explored in detail. The computational scaling of the method developed is the same as canonical second order Møller-Plesset perturbation theory (fifth order in the number of molecular orbitals), but its accuracy competes with the high-accuracy, high-cost standard CCSD(T), even when the latter is allowed to break spin-symmetry. The variation presented can be implemented without explicit calculation and storage of the most expensive energy contributions, thereby improving the range of systems which can be treated. The performance and scaling of the method are demonstrated with calculations on the water, fluorine, and oxirane molecules, and compared to the parent model.

  5. High-order micro-ring resonator with perfect transmission using symmetrical Fibonacci structures.

    PubMed

    Tsao, C W; Cheng, Y H; Hsueh, W J

    2015-09-15

    A symmetrical Fibonacci micro-ring resonator (SFMR) has been presented to avoid the coupled resonator optical waveguide (CROW) bottle, which is a bottle-shaped distribution for high orders in transmission spectra. The SFMR features three advantages that improve filtering quality compared to that provided by traditional periodic micro-ring resonators. First, sharper resonances are obtained by eliminating the CROW bottle from the mini gaps that appear in the major-band region. Second, peaks with perfect transmission are always obtained without a radius and coupling modulation in the mini-band regions and major-band regions. Third, the full width at half-maximum of the band-edge peak decreases with the increasing generation order.

  6. Improved Culture Medium (TiKa) for Mycobacterium avium Subspecies Paratuberculosis (MAP) Matches qPCR Sensitivity and Reveals Significant Proportions of Non-viable MAP in Lymphoid Tissue of Vaccinated MAP Challenged Animals

    PubMed Central

    Bull, Tim J.; Munshi, Tulika; Mikkelsen, Heidi; Hartmann, Sofie B.; Sørensen, Maria R.; Garcia, Joanna S.; Lopez-Perez, Paula M.; Hofmann, Sven; Hilpert, Kai; Jungersen, Gregers

    2017-01-01

    The quantitative detection of viable pathogen load is an important tool in determining the degree of infection in animals and contamination of foodstuffs. Current conventional culture methods are limited in their ability to determine these levels in Mycobacterium avium subspecies paratuberculosis (MAP) due to slow growth, clumping and low recoverability issues. The principle goal of this study was to evaluate a novel culturing process (TiKa) with unique ability to stimulate MAP growth from low sample loads and dilutions. We demonstrate it was able to stimulate a mean 29-fold increase in recoverability and an improved sensitivity of up to three logs when compared with conventional culture. Using TiKa culture, MAP clumping was minimal and produced visible colonies in half the time required by standard culture methods. Parallel quantitative evaluation of the TiKa culture approach and qPCR on MAP loads in tissue and gut mucosal samples from a MAP vaccine-challenge study, showed good correlations between colony counts (cfu) and qPCR derived genome equivalents (Geq) over a large range of loads with a 30% greater sensitivity for TiKa culture approach at low loads (two logs). Furthermore, the relative fold changes in Geq and cfu from the TiKa culture approach suggests that non-mucosal tissue loads from MAP infected animals contained a reduced proportion of non-viable MAP (mean 19-fold) which was reduced significantly further (mean 190-fold) in vaccinated “reactor” calves. This study shows TiKa culture equates well with qPCR and provides important evidence that accuracy in estimating viable MAP load using DNA tests alone may vary significantly between samples of mucosal and lymphatic origin. PMID:28101082

  7. Improved Culture Medium (TiKa) for Mycobacterium avium Subspecies Paratuberculosis (MAP) Matches qPCR Sensitivity and Reveals Significant Proportions of Non-viable MAP in Lymphoid Tissue of Vaccinated MAP Challenged Animals.

    PubMed

    Bull, Tim J; Munshi, Tulika; Mikkelsen, Heidi; Hartmann, Sofie B; Sørensen, Maria R; Garcia, Joanna S; Lopez-Perez, Paula M; Hofmann, Sven; Hilpert, Kai; Jungersen, Gregers

    2016-01-01

    The quantitative detection of viable pathogen load is an important tool in determining the degree of infection in animals and contamination of foodstuffs. Current conventional culture methods are limited in their ability to determine these levels in Mycobacterium avium subspecies paratuberculosis (MAP) due to slow growth, clumping and low recoverability issues. The principle goal of this study was to evaluate a novel culturing process (TiKa) with unique ability to stimulate MAP growth from low sample loads and dilutions. We demonstrate it was able to stimulate a mean 29-fold increase in recoverability and an improved sensitivity of up to three logs when compared with conventional culture. Using TiKa culture, MAP clumping was minimal and produced visible colonies in half the time required by standard culture methods. Parallel quantitative evaluation of the TiKa culture approach and qPCR on MAP loads in tissue and gut mucosal samples from a MAP vaccine-challenge study, showed good correlations between colony counts (cfu) and qPCR derived genome equivalents (Geq) over a large range of loads with a 30% greater sensitivity for TiKa culture approach at low loads (two logs). Furthermore, the relative fold changes in Geq and cfu from the TiKa culture approach suggests that non-mucosal tissue loads from MAP infected animals contained a reduced proportion of non-viable MAP (mean 19-fold) which was reduced significantly further (mean 190-fold) in vaccinated "reactor" calves. This study shows TiKa culture equates well with qPCR and provides important evidence that accuracy in estimating viable MAP load using DNA tests alone may vary significantly between samples of mucosal and lymphatic origin.

  8. Rotation and scale change invariant point pattern relaxation matching by the Hopfield neural network

    NASA Astrophysics Data System (ADS)

    Sang, Nong; Zhang, Tianxu

    1997-12-01

    Relaxation matching is one of the most relevant methods for image matching. The original relaxation matching technique using point patterns is sensitive to rotations and scale changes. We improve the original point pattern relaxation matching technique to be invariant to rotations and scale changes. A method that makes the Hopfield neural network perform this matching process is discussed. An advantage of this is that the relaxation matching process can be performed in real time with the neural network's massively parallel capability to process information. Experimental results with large simulated images demonstrate the effectiveness and feasibility of the method to perform point patten relaxation matching invariant to rotations and scale changes and the method to perform this matching by the Hopfield neural network. In addition, we show that the method presented can be tolerant to small random error.

  9. Reducing the likelihood of long tennis matches.

    PubMed

    Barnett, Tristan; Alan, Brown; Pollard, Graham

    2006-01-01

    Long matches can cause problems for tournaments. For example, the starting times of subsequent matches can be substantially delayed causing inconvenience to players, spectators, officials and television scheduling. They can even be seen as unfair in the tournament setting when the winner of a very long match, who may have negative aftereffects from such a match, plays the winner of an average or shorter length match in the next round. Long matches can also lead to injuries to the participating players. One factor that can lead to long matches is the use of the advantage set as the fifth set, as in the Australian Open, the French Open and Wimbledon. Another factor is long rallies and a greater than average number of points per game. This tends to occur more frequently on the slower surfaces such as at the French Open. The mathematical method of generating functions is used to show that the likelihood of long matches can be substantially reduced by using the tiebreak game in the fifth set, or more effectively by using a new type of game, the 50-40 game, throughout the match. Key PointsThe cumulant generating function has nice properties for calculating the parameters of distributions in a tennis matchA final tiebreaker set reduces the length of matches as currently being used in the US OpenA new 50-40 game reduces the length of matches whilst maintaining comparable probabilities for the better player to win the match.

  10. The Johns Hopkins Venous Thromboembolism Collaborative: Multidisciplinary team approach to achieve perfect prophylaxis.

    PubMed

    Streiff, Michael B; Lau, Brandyn D; Hobson, Deborah B; Kraus, Peggy S; Shermock, Kenneth M; Shaffer, Dauryne L; Popoola, Victor O; Aboagye, Jonathan K; Farrow, Norma A; Horn, Paula J; Shihab, Hasan M; Pronovost, Peter J; Haut, Elliott R

    2016-12-01

    Venous thromboembolism (VTE) is an important cause of preventable harm in hospitalized patients. The critical steps in delivery of optimal VTE prevention care include (1) assessment of VTE and bleeding risk for each patient, (2) prescription of risk-appropriate VTE prophylaxis, (3) administration of risk-appropriate VTE prophylaxis in a patient-centered manner, and (4) continuously monitoring outcomes to identify new opportunities for learning and performance improvement. To ensure that every hospitalized patient receives VTE prophylaxis consistent with their individual risk level and personal care preferences, we organized a multidisciplinary task force, the Johns Hopkins VTE Collaborative. To achieve the goal of perfect prophylaxis for every patient, we developed evidence-based, specialty-specific computerized clinical decision support VTE prophylaxis order sets that assist providers in ordering risk-appropriate VTE prevention. We developed novel strategies to improve provider VTE prevention ordering practices including face-to-face performance reviews, pay for performance, and provider VTE scorecards. When we discovered that prescription of risk-appropriate VTE prophylaxis does not ensure its administration, our multidisciplinary research team conducted in-depth surveys of patients, nurses, and physicians to design a multidisciplinary patient-centered educational intervention to eliminate missed doses of pharmacologic VTE prophylaxis that has been funded by the Patient Centered Outcomes Research Institute. We expect that the studies currently underway will bring us closer to the goal of perfect VTE prevention care for every patient. Our learning journey to eliminate harm from VTE can be applied to other types of harm. Journal of Hospital Medicine 2016;11:S8-S14. © 2016 Society of Hospital Medicine.

  11. Increasing the effectiveness of messages promoting responsible undergraduate drinking: tailoring to personality and matching to context.

    PubMed

    York, Valerie K; Brannon, Laura A; Miller, Megan M

    2012-01-01

    This study addressed the serious problem of college student binge drinking by identifying factors that improve the effectiveness of messages encouraging responsible drinking presented through a website simulation. We tested schema matching (i.e., whether the message matches the person's self-schema type or not) and two types of context matching (i.e., whether the message matches the topic or values of the message context) to determine their relative influence on the effectiveness of the message. We expected that messages matched to any of these factors would be more effective than messages not matched. Schema matching reduced intentions to drink while staying in/home, but topic matching reduced intentions to drink when going out, suggesting that different factors are important for messages targeting drinking behavior in different locations. Significant interactions between topic matching and value matching on message evaluation variables indicated that the message should not match the message context too closely. That is, there appears to be a matching threshold: Increasing the number of factors the message matches does not increase message effectiveness, possibly because it makes the message too redundant with the surrounding content.

  12. Selecting an appropriate caliper can be essential for achieving good balance with propensity score matching.

    PubMed

    Lunt, Mark

    2014-01-15

    Matching on the propensity score is widely used to estimate the effect of an exposure in observational studies. However, the quality of the matches can be affected by decisions made during the matching process, particularly the order in which subjects are selected for matching and the maximum permitted difference between matched subjects (the "caliper"). This study used simulations to explore the effects of these decisions on both the imbalance of covariates and the closeness of matching, while allowing the numbers of potential matches and strengths of association between the confounding variable and the exposure to vary. It was found that, without a caliper, substantial bias was possible, particularly with a relatively small reservoir of potential matches and strong confounder-exposure association. Use of the recommended caliper reduced the bias considerably, but bias remained if subjects were selected by increasing or decreasing propensity score. A tighter caliper led to greatly reduced bias and closer matches, although some subjects could not be matched. This study suggests that a narrow caliper can improve the performance of propensity score matching. In situations where it is impossible to find appropriate matches for all exposed subjects, it is better to select subjects in order of the best available matches, rather than increasing or decreasing the propensity score.

  13. Pyrolytic Graphite Foam: A Passive Magnetic Susceptibility Matching Material

    PubMed Central

    Lee, Gary C.; Goodwill, Patrick W.; Phuong, Kevin; Inglis, Ben A.; Scott, Greig C.; Hargreaves, Brian A.; Li, Lizabeth; Chen, Alex C.; Shah, Rachana N.; Conolly, Steven M.

    2012-01-01

    Purpose To evaluate a novel soft, lightweight cushion that can match the magnetic susceptibility of human tissue. The magnetic susceptibility difference between air and tissue produces field inhomogeneities in the B0 field, which leads to susceptibility artifacts in MR studies. Materials and Methods Pyrolytic graphite (PG) microparticles are uniformly embedded into a foam cushion to reduce or eliminate field inhomogeneities at accessible air and tissue interfaces. 3T MR images and field maps of an air/water/PG foam phantom were acquired. Q measurements on a 4T tuned head coil and pulse sequence heating tests at 3T were also performed. Results The PG foam improved susceptibility matching, reduced the field perturbations in phantoms, does not heat, and is non-conductive. Conclusion The susceptibility matched PG foam is lightweight, safe for patient use, adds no noise or MRI artifacts, is compatible with RF coil arrays, and improves B0 homogeneity, which enables more robust MR studies. PMID:20815067

  14. Robust feature point matching with sparse model.

    PubMed

    Jiang, Bo; Tang, Jin; Luo, Bin; Lin, Liang

    2014-12-01

    Feature point matching that incorporates pairwise constraints can be cast as an integer quadratic programming (IQP) problem. Since it is NP-hard, approximate methods are required. The optimal solution for IQP matching problem is discrete, binary, and thus sparse in nature. This motivates us to use sparse model for feature point matching problem. The main advantage of the proposed sparse feature point matching (SPM) method is that it generates sparse solution and thus naturally imposes the discrete mapping constraints approximately in the optimization process. Therefore, it can optimize the IQP matching problem in an approximate discrete domain. In addition, an efficient algorithm can be derived to solve SPM problem. Promising experimental results on both synthetic points sets matching and real-world image feature sets matching tasks show the effectiveness of the proposed feature point matching method.

  15. Thermally matched fluid cooled power converter

    DOEpatents

    Radosevich, Lawrence D.; Kannenberg, Daniel G.; Kaishian, Steven C.; Beihoff, Bruce C.

    2005-06-21

    A thermal support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. Power electronic circuits are thermally matched, such as between component layers and between the circuits and the support. The support may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

  16. Resistance after firing protected electric match

    DOEpatents

    Montoya, Arsenio P.

    1981-11-10

    An electric match having electrical leads embedded in flame-producing compound is protected against an accidental resistance across the leads after firing by a length of heat-shrinkable tubing encircling the match body and having a skirt portion extending beyond the leads. The heat of the burning match and an adjacent thermal battery causes the tubing to fold over the end of the match body, covering the ends of the leads and protecting them from molten pieces of the battery.

  17. Study of the index matching for different photopolymers

    NASA Astrophysics Data System (ADS)

    Fernández, Roberto; Gallego, Sergi; Márquez, Andrés.; Ortuño, Manuel; Marini, Stephan; Pascual, Inmaculada; Beléndez, Augusto

    2015-09-01

    One of the most promising phase optical recording mediums are photopolymers. In these materials, the use of an index matching component permits a better conservation of the stored information and, additionally, the study of the molecules migration and shrinkage/swelling phenomena separately. In general, the transmitted beam has the information of the thickness and refractive index modulation mixed. Therefore, we propose the introduction of a coverplate besides with an index matching liquid in order to improve the characterization and the conservation. The index matching techniques have been classically used for holographic recording materials. In principle, to obtain an accurate index matching we have to choose a liquid with refractive index very close to the mean of the polymer one. Then, when shrinkage takes place during recording, mainly due to the polymerization, the liquid will fill up the generated grooves minimizing the diffractive effects produced by the relief structure. In fact, in this work we study different index matching components for different photopolymers. The photopolymers analyzed in this work have a polyvinyl alcohol (PVA) as a binder and two different main monomers: one has acrylamide and the other one sodium acrylate. We have recorded very low diffractive gratings and studied their conservation for different index matching components.

  18. A beam-matching concept for medical linear accelerators.

    PubMed

    Sjöström, David; Bjelkengren, Ulf; Ottosson, Wiviann; Behrens, Claus F

    2009-01-01

    The flexibility in radiotherapy can be improved if a patient can be moved between any one of the department's medical linear accelerators without the need to change anything in the patient's treatment plan. For this to be possible, the dosimetric characteristics of the various accelerators must be the same, or nearly the same i.e. the accelerators must be beam-matched. During a period of nine months, eight Varian iX accelerators with 6 and 15 MV photon beams and 6-18 MeV electron beams (only four of the eight) were installed at our clinic. All accelerators fulfilled the vendor-defined "fine beam-match" criteria, and a more extensive set of measurements was carried out during commissioning. The measured absorbed dose data for each accelerator were compared with the first accelerator, chosen as reference, and the TPS calculations. Two of the eight accelerators showed a larger discrepancy for the 15 MV beam not revealed by the vendor-defined acceptance criteria, whereas the other six accelerators were satisfactorily matched. The beam-matching acceptance criteria defined by the vendor are not strict enough to guarantee optimal beam-match. Deviations related to dose calculations and to beam-matched accelerators may add up. The safest and most practical way to ensure that all accelerators are within clinical acceptable accuracy is to include TPS calculations in the evaluation. Further, comparisons between measurements and calculations should be done in absolute dose terms.

  19. Robust matching for voice recognition

    NASA Astrophysics Data System (ADS)

    Higgins, Alan; Bahler, L.; Porter, J.; Blais, P.

    1994-10-01

    This paper describes an automated method of comparing a voice sample of an unknown individual with samples from known speakers in order to establish or verify the individual's identity. The method is based on a statistical pattern matching approach that employs a simple training procedure, requires no human intervention (transcription, work or phonetic marketing, etc.), and makes no assumptions regarding the expected form of the statistical distributions of the observations. The content of the speech material (vocabulary, grammar, etc.) is not assumed to be constrained in any way. An algorithm is described which incorporates frame pruning and channel equalization processes designed to achieve robust performance with reasonable computational resources. An experimental implementation demonstrating the feasibility of the concept is described.

  20. Ontology Matching with Semantic Verification

    PubMed Central

    Jean-Mary, Yves R.; Shironoshita, E. Patrick; Kabuka, Mansur R.

    2009-01-01

    ASMOV (Automated Semantic Matching of Ontologies with Verification) is a novel algorithm that uses lexical and structural characteristics of two ontologies to iteratively calculate a similarity measure between them, derives an alignment, and then verifies it to ensure that it does not contain semantic inconsistencies. In this paper, we describe the ASMOV algorithm, and then present experimental results that measure its accuracy using the OAEI 2008 tests, and that evaluate its use with two different thesauri: WordNet, and the Unified Medical Language System (UMLS). These results show the increased accuracy obtained by combining lexical, structural and extensional matchers with semantic verification, and demonstrate the advantage of using a domain-specific thesaurus for the alignment of specialized ontologies. PMID:20186256

  1. Mechanism of resonant perfect optical absorption in dielectric film supporting metallic grating structures.

    PubMed

    Chen, Xiumei; Yan, Xiaopeng; Li, Ping; Mou, Yongni; Wang, Wenqiang; Guan, Zhiqiang; Xu, Hongxing

    2016-08-22

    The mechanism of resonant perfect optical absorbers is quantitatively revealed by the coupled mode method for the air/grating/dielectric film/air four region system. The sufficient and necessary conditions of the perfect optical absorption are derived from the interface scattering coefficients analyses. The coupling of the Fabry-Perot modes in the grating slits and non-zero order quasi waveguide modes in the dielectric film play a key role for the perfect optical absorption when the light is incident from the grating side. The analytical sufficient and necessary conditions of the perfect optical absorption provide an efficient tool towards geometry design for the perfect optical absorption at the specific wavelengths. The advantages of a widely tunable perfect optical absorption wavelength, a high Q factor and the confined energy loss on metal surfaces make the air/grating/film/air structures promising for applications in sensing, modulation and detection.

  2. Group-velocity-matched optical parametric oscillator in tilted quasi-phase-matched gratings.

    PubMed

    Zhang, Wei Quan

    2006-07-10

    An achromatic phase-matching scheme is reported for an optical parametric oscillator in tilted quasi-phase-matched gratings. The spectral angular dispersion is introduced in interaction waves such that each wave component satisfies the two-dimensional (noncollinear) quasi-phase matching. This is equivalent to simultaneous quasi-phase matching and group-velocity matching for ultrashort pulses. The phase-matching bandwidth for 10 mm periodically poled KTP increases by a factor of 12 at lambdas = 1.7 microm compared with one-dimensional quasi-phase matching. The effective interaction length will increase as a result of the matching.

  3. A truncation hierarchy of coupled cluster models of strongly correlated systems based on perfect-pairing references: The singles+doubles models

    NASA Astrophysics Data System (ADS)

    Parkhill, John A.; Head-Gordon, Martin

    2010-09-01

    Paired, active-space treatments of static correlation are augmented with additional amplitudes to produce a hierarchy of parsimonious and efficient cluster truncations that approximate the total energy. The number of parameters introduced in these models grow with system size in a tractable way: two powers larger than the static correlation model it is built upon: for instance cubic for the models built on perfect pairing, fourth order for a perfect quadruples (PQ) reference, and fifth order for the models built on perfect hextuples. These methods are called singles+doubles (SD) corrections to perfect pairing, PQ, perfect hextuples, and two variants are explored. An implementation of the SD methods is compared to benchmark results for F2 and H2O dissociation problems, the H4 and H8 model systems, and the insertion of beryllium into hydrogen. In the cases examined even the quartic number of parameters associated with PQSD is able to provide results which meaningfully improve on coupled-cluster singles doubles (CCSD) (which also has quartic amplitudes) and compete with existing multi-reference alternatives.

  4. Matching and conditioned reinforcement rate.

    PubMed

    Shahan, Timothy A; Podlesnik, Christopher A; Jimenez-Gomez, Corina

    2006-03-01

    Attempts to examine the effects of variations in relative conditioned reinforcement rate on choice have been confounded by changes in rates of primary reinforcement or changes in the value of the conditioned reinforcer. To avoid these problems, this experiment used concurrent observing responses to examine sensitivity of choice to relative conditioned reinforcement rate. In the absence of observing responses, unsignaled periods of food delivery on a variable-interval 90-s schedule alternated with extinction on a center key (i.e., a mixed schedule was in effect). Two concurrently available observing responses produced 15-s access to a stimulus differentially associated with the schedule of food delivery (S+). The relative rate of S+ deliveries arranged by independent variable-interval schedules for the two observing responses varied across conditions. The relation between the ratio of observing responses and the ratio of S+ deliveries was well described by the generalized matching law, despite the absence of changes in the rate of food delivery. In addition, the value of the S+ deliveries likely remained constant across conditions because the ratio of S+ to mixed schedule food deliveries remained constant. Assuming that S+ deliveries serve as conditioned reinforcers, these findings are consistent with the functional similarity between primary and conditioned reinforcers suggested by general choice theories based on the concatenated matching law (e.g., contextual choice and hyperbolic value-added models). These findings are inconsistent with delay reduction theory, which has no terms for the effects of rate of conditioned reinforcement in the absence of changes in rate of primary reinforcement.

  5. 7 CFR 3405.5 - Matching funds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Matching funds. 3405.5 Section 3405.5 Agriculture Regulations of the Department of Agriculture (Continued) COOPERATIVE STATE RESEARCH, EDUCATION, AND EXTENSION... Matching funds. Each application must provide for matching support from a non-Federal source. CSREES...

  6. 13 CFR 102.40 - Computer matching.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false Computer matching. 102.40 Section... Protection of Privacy and Access to Individual Records Under the Privacy Act of 1974 § 102.40 Computer matching. The OCIO will enforce the computer matching provisions of the Privacy Act. The FOI/PA Office...

  7. 39 CFR 266.10 - Computer matching.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Computer matching. 266.10 Section 266.10 Postal... Computer matching. (a) General. Any agency or Postal Service component that wishes to use records from a... records must submit its proposal to the Postal Service Manager Records Office. Computer matching...

  8. 39 CFR 266.10 - Computer matching.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Computer matching. 266.10 Section 266.10 Postal... Computer matching. (a) General. Any agency or Postal Service component that wishes to use records from a... records must submit its proposal to the Postal Service Manager Records Office. Computer matching...

  9. 13 CFR 102.40 - Computer matching.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Computer matching. 102.40 Section... Protection of Privacy and Access to Individual Records Under the Privacy Act of 1974 § 102.40 Computer matching. The OCIO will enforce the computer matching provisions of the Privacy Act. The FOI/PA Office...

  10. 13 CFR 102.40 - Computer matching.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 13 Business Credit and Assistance 1 2013-01-01 2013-01-01 false Computer matching. 102.40 Section... Protection of Privacy and Access to Individual Records Under the Privacy Act of 1974 § 102.40 Computer matching. The OCIO will enforce the computer matching provisions of the Privacy Act. The FOI/PA Office...

  11. 39 CFR 266.10 - Computer matching.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 39 Postal Service 1 2014-07-01 2014-07-01 false Computer matching. 266.10 Section 266.10 Postal... Computer matching. (a) General. Any agency or Postal Service component that wishes to use records from a... records must submit its proposal to the Postal Service Manager Records Office. Computer matching...

  12. 39 CFR 266.10 - Computer matching.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 39 Postal Service 1 2013-07-01 2013-07-01 false Computer matching. 266.10 Section 266.10 Postal... Computer matching. (a) General. Any agency or Postal Service component that wishes to use records from a... records must submit its proposal to the Postal Service Manager Records Office. Computer matching...

  13. 13 CFR 102.40 - Computer matching.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false Computer matching. 102.40 Section... Protection of Privacy and Access to Individual Records Under the Privacy Act of 1974 § 102.40 Computer matching. The OCIO will enforce the computer matching provisions of the Privacy Act. The FOI/PA Office...

  14. 39 CFR 266.10 - Computer matching.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 39 Postal Service 1 2012-07-01 2012-07-01 false Computer matching. 266.10 Section 266.10 Postal... Computer matching. (a) General. Any agency or Postal Service component that wishes to use records from a... records must submit its proposal to the Postal Service Manager Records Office. Computer matching...

  15. 13 CFR 102.40 - Computer matching.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 13 Business Credit and Assistance 1 2014-01-01 2014-01-01 false Computer matching. 102.40 Section... Protection of Privacy and Access to Individual Records Under the Privacy Act of 1974 § 102.40 Computer matching. The OCIO will enforce the computer matching provisions of the Privacy Act. The FOI/PA Office...

  16. Image Matching Using Generalized Hough Transforms

    NASA Technical Reports Server (NTRS)

    Davis, L. S.; Hu, F. P.; Hwang, V.; Kitchen, L.

    1983-01-01

    An image matching system specifically designed to match dissimilar images is described. A set of blobs and ribbons is first extracted from each image, and then generalized Hough transform techniques are used to match these sets and compute the transformation that best registers the image. An example of the application of the approach to one pair of remotely sensed images is presented.

  17. Database crime to crime match rate calculation.

    PubMed

    Buckleton, John; Bright, Jo-Anne; Walsh, Simon J

    2009-06-01

    Guidance exists on how to count matches between samples in a crime sample database but we are unable to locate a definition of how to estimate a match rate. We propose a method that does not proceed from the match counting definition but which has a strong logic.

  18. 24 CFR 92.221 - Match credit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Match credit. 92.221 Section 92.221... INVESTMENT PARTNERSHIPS PROGRAM Program Requirements Matching Contribution Requirement § 92.221 Match credit. (a) When credit is given. Contributions are credited on a fiscal year basis at the time...

  19. 24 CFR 92.221 - Match credit.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 1 2014-04-01 2014-04-01 false Match credit. 92.221 Section 92.221... INVESTMENT PARTNERSHIPS PROGRAM Program Requirements Matching Contribution Requirement § 92.221 Match credit. (a) When credit is given. Contributions are credited on a fiscal year basis at the time...

  20. 24 CFR 92.221 - Match credit.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 1 2013-04-01 2013-04-01 false Match credit. 92.221 Section 92.221... INVESTMENT PARTNERSHIPS PROGRAM Program Requirements Matching Contribution Requirement § 92.221 Match credit. (a) When credit is given. Contributions are credited on a fiscal year basis at the time...